Why Children Forget What They've Learned — And How to Make Learning Stick

Understanding memory, retrieval practice and the science of learning Your child could recognise every phonics sound yesterday, but today they cannot remember half of them. Last week, they confidently explained the difference between a planet and a star. This week, they seem unsure.

You spent an entire afternoon exploring fractions, working through examples and answering questions together. Everything appeared to make sense. Yet, when you return to the topic a few days later, it feels as though you're starting again. Sound familiar?

For parents supporting their children's education, particularly those home educating, this can be frustrating. You might wonder whether your child was paying attention, whether you explained something incorrectly or whether they simply need more practice. But forgetting is a normal part of how human memory works.

Understanding why children forget, and what helps them remember, can completely change how we approach learning. The answer isn't necessarily longer lessons, more worksheets or repeating the same explanation over and over again. Sometimes, it is about changing when and how children revisit what they've learned.

Why do children forget things they've already learned?

To understand forgetting, we first need to understand the difference between learning something in the moment and being able to remember it later. Imagine teaching your child the phoneme /ai/ and showing them the graphemes ai, ay and a-e.

During the lesson, they successfully identify the spellings, read several words and complete an activity. It appears they have understood everything. However, recognising something immediately after it has been explained is not the same as being able to retrieve that knowledge independently several days later.

Working memory and long-term memory

Our working memory allows us to temporarily hold and use information. It has a limited capacity, particularly when we are dealing with unfamiliar material. Long-term memory stores knowledge and experiences that may be accessible over much longer periods.

When children first encounter something new, they rely heavily on working memory. For example, a child learning to read the word ship might need to concentrate on identifying sh, recognising the other graphemes and blending the phonemes together. For a more experienced reader, these processes are much more automatic.

As knowledge becomes increasingly secure and accessible in long-term memory, children can devote more attention to understanding what they read rather than concentrating on every individual word. However, one successful lesson does not guarantee that new knowledge has become secure in long-term memory. Children need opportunities to revisit, retrieve and use that knowledge.

The forgetting curve: Why learning fades over time

In the nineteenth century, psychologist Hermann Ebbinghaus investigated how memory changes over time. His research helped establish what became known as the forgetting curve: the general tendency for our ability to recall information to decline as time passes without further learning or retrieval. Although the original experiments involved Ebbinghaus learning unfamiliar syllables himself, rather than children learning school subjects, the broader principle has influenced subsequent memory research. We forget some information relatively quickly, particularly when it is unfamiliar, weakly learned or rarely revisited.

This helps explain why a child might confidently answer questions immediately after a lesson but struggle with the same questions a week later. It also challenges an assumption we sometimes make about education: Just because something has been taught does not mean it has been securely learned. And just because something has been learned does not mean it will remain easily accessible without further practice. Fortunately, research suggests there are effective ways to strengthen retention.

1. Retrieval practice: Helping children remember by remembering

One of the most useful findings from cognitive psychology is that retrieving information from memory can strengthen future retention.

This is known as retrieval practice. Instead of always showing children information again, we give them opportunities to recall it themselves. For example, imagine your child learned about the planets yesterday. Today, you could show them the same diagram and explain the names again. Alternatively, you could ask:

"Can you remember which planet is closest to the Sun?"

"Which planet has rings?"

"What do you remember about Earth?"

When your child attempts to retrieve this information, they are doing more than demonstrating what they know. The act of successful retrieval can help strengthen later memory. This effect has been demonstrated in research, including work by Roediger and Karpicke (2006), which compared repeated studying with opportunities to retrieve previously learned material.

What does retrieval practice look like at home?

It doesn't need to involve formal tests. You might ask your child to:

• Recall three things they learned yesterday.

• Explain a concept without looking at their notes.

• Write down the phonemes they remember.

• Draw a diagram from memory before checking it.

• Retell the main events of a story.

• Answer a few questions from a previous lesson.

For younger children, retrieval can be playful. You could hide picture cards and ask them to remember what was underneath, practise previously taught sounds using flashcards or play a quick question-and-answer game.

The important point is that children have an opportunity to think before being shown the answer. However, retrieval practice should not become an exercise in repeatedly testing children on things they cannot remember. If a child struggles, provide a clue, model the answer or revisit the material. Feedback matters, and repeated unsuccessful guessing is not the goal.

2. Spaced practice: Why a little over time can be better than a lot at once

Imagine two approaches to learning spellings. In the first, a child practises ten spellings for forty minutes on Monday and doesn't revisit them until the following week.

In the second, they practise for ten minutes on Monday, Tuesday, Thursday and Saturday. Both approaches involve forty minutes of practice. However, research on distributed or spaced practice suggests that spreading learning across time generally supports longer-term retention better than concentrating the same amount of study into one session.

A major review by Cepeda and colleagues (2006) found substantial evidence for the benefits of distributed practice across numerous experiments. Why?

Because returning to information after some time has passed often requires the learner to retrieve it again. That effort can be useful.

How to use spaced practice in home education

Suppose your child learns a new grapheme on Monday. A possible routine might look like this:

This is an example rather than a fixed research-prescribed schedule. The ideal spacing depends on the child, the difficulty of the material and how securely it has been learned.

The principle is straightforward: Revisit knowledge before it disappears from regular use, and continue revisiting it as children become more confident.

This is particularly important in phonics, mathematics, vocabulary and other subjects where later learning builds on earlier knowledge.

3. Interleaving: Mixing old and new learning

Another useful strategy is interleaving. Interleaving involves mixing different but related types of problems or material during practice rather than completing every example of one type before moving to another. For example, a child might practise ten addition questions followed by ten subtraction questions.

Alternatively, they might practise a carefully selected mixture of addition and subtraction questions. The second approach requires them to recognise which operation is appropriate rather than simply repeating the same procedure.

Research suggests that interleaving can be beneficial in certain learning situations, particularly where learners need to distinguish between related concepts or problem types.

What does this look like in phonics?

Imagine your child has learned:

• ai in rain

• ay in play

• a-e in cake

Initially, each spelling should be explicitly introduced and practised. Once the child has some familiarity with them, you might mix words containing the different graphemes.

This encourages the child to attend carefully to the spelling patterns rather than assuming every word uses the same grapheme. However, interleaving should not replace clear initial instruction. Mixing too many unfamiliar concepts together can overwhelm children.

Teach clearly first. Then provide carefully structured opportunities to discriminate between and retrieve what has been taught.

4. Prior knowledge: Why some things are easier to remember

Have you noticed how children can remember extraordinary amounts of information about something they love?

A child fascinated by dinosaurs might remember complicated names, different geological periods and which species were herbivores. Another child might recall facts about football teams, animals or the Solar System with remarkable accuracy.

Interest can encourage attention and repeated engagement, but another important factor is prior knowledge. When children already know something about a subject, new information can connect to existing knowledge. For example, a child who understands that Earth rotates may find it easier to understand explanations of day and night.

A child who knows the sounds represented by common graphemes can use that knowledge when learning to read increasingly complex words. Learning is not simply collecting disconnected facts. It involves developing organised knowledge that helps us interpret and understand new information.

How can parents use this?

Before introducing a new topic, ask:

"What do we already know about this?"

If you're learning about the Moon, revisit what your child already understands about Earth and the Sun.

If you're introducing fractions, revisit equal parts and sharing.

If you're teaching a new phonics pattern, retrieve previously taught grapheme–phoneme correspondences.

These small connections help new learning build on more secure foundations.

5. Why repeating an explanation isn't always enough

When a child forgets something, our natural response is often to explain it again. Sometimes, that is exactly what is needed. But if we only ever repeat the explanation, children may become increasingly familiar with the information without developing the ability to recall it independently. This is the difference between recognition and retrieval.

Imagine showing your child the word train. They recognise it and read it successfully. Later, you ask them to spell train without seeing the word. Now they must identify the phonemes and retrieve the correct graphemes.

The second task places different demands on memory. This is one reason why reading and spelling, although closely connected, do not always develop at exactly the same rate. It also illustrates why effective practice should include opportunities for children to use knowledge without having the answer directly in front of them.

6. Sleep, breaks and attention matter too

Memory is not only influenced by what happens during a lesson.

Sleep plays an important role in memory consolidation, the processes through which newly acquired information becomes more stable over time.

Attention also matters. When children are tired, distracted or overwhelmed, they may struggle to process and retain new information.

This doesn't mean every learning difficulty can be solved by taking a break or getting more sleep. But it does mean that longer sessions are not automatically more effective. For some children, a short, focused lesson followed by opportunities to revisit the material may be more productive than a lengthy session in which concentration steadily declines.

Parents can support this by making space for breaks, keeping expectations developmentally appropriate and noticing when a child needs additional explanation rather than simply more repetition.

7. What should you do when your child forgets?

The next time your child cannot remember something they appeared to understand yesterday, try approaching it as useful information. Rather than immediately concluding that they weren't listening or that the lesson was unsuccessful, consider what their response tells you.

Step 1: Check what they can remember.

Ask a simple question or invite them to explain what they know. Avoid giving away the answer immediately.

Step 2: Offer a helpful prompt.

A picture, the first sound or a partially completed example may help them access the information.

Step 3: Reteach if necessary.

If the knowledge is not secure, explain it again using clear modelling and guided practice.

Step 4: Revisit it later.

Include the material in short retrieval opportunities over the following days and weeks.

Step 5: Look for progress over time.

Notice whether your child needs fewer prompts, recalls information more quickly or can apply it in new situations.

A child who needs three prompts today but only one next week may be making meaningful progress, even if their learning isn't perfectly consistent.

8. Making learning stick without overwhelming your child

One of the advantages of home education is the flexibility to revisit learning according to your child's needs. You don't necessarily have to wait until a particular topic appears again in a textbook or scheme of work. You can build small retrieval opportunities into everyday learning. For example:

During phonics: Begin with a few previously taught sounds before introducing something new.

During reading: Ask your child to recall what happened in the previous chapter before continuing.

During maths: Include two or three questions from an earlier topic alongside current learning.

During science: Ask your child to explain something they learned last week before introducing the next concept.

During history: Revisit important events using a timeline and ask children to explain how they connect.

The aim isn't to constantly quiz children throughout the day. It's to make revisiting knowledge a normal, manageable part of learning. And importantly, not every activity needs to be new or exciting. Sometimes the most valuable learning happens when children return to something familiar and discover that they can now do it more independently.

Research and further reading

The following research provides a foundation for the learning strategies discussed in this article.

1. Ebbinghaus, H. (1885). Memory: A Contribution to Experimental Psychology. Foundational experimental work on memory and forgetting.

2. Roediger, H. L. & Karpicke, J. D. (2006). Test-Enhanced Learning: Psychological Science, 17(3), 249–255. Read the research

3. Cepeda, N. J. et al. (2006). Distributed Practice in Verbal Recall Tasks: A Review and Quantitative Synthesis. Psychological Bulletin, 132(3), 354–380. Read the research

4. Dunlosky, J. et al. (2013). Improving Students' Learning With Effective Learning Techniques. Psychological Science in the Public Interest, 14(1), 4–58. Read the review

5. Education Endowment Foundation. Metacognition and Self-Regulated Learning. Explore the guidance