Why Don’t We Remember What We Learned in School?

And what Thai education can learn from the science of learning

If I asked you today, “How much of what you learned in high school can you still remember?”
Some of us might recall a few fun English classes, a favorite teacher, or maybe a formula or two. But for most people, the honest answer is: very little.

This raises an uncomfortable question.
Why is it that after spending more than a decade studying, often very hard, we struggle to apply that knowledge in real life?

Was it because we didn’t study enough?
Or is it possible that we were studying the wrong way?

The illusion of learning

Recently, I’ve been diving into what’s often called learning science, research grounded in cognitive psychology and neuroscience that explains how people actually learn. One book that clearly lays out these principles, supported by decades of scientific evidence, is Make It Stick by Peter C. Brown, Henry L. Roediger III, and Mark A. McDaniel

One of the book’s most important insights is this:

We are poor judges of when learning is effective.

In other words, feeling productive doesn’t mean learning is happening.

Many students believe the best way to prepare for exams is rereading notes, highlighting textbooks, or doing the same type of practice repeatedly until it feels familiar. These methods feel comfortable. They feel efficient. And that’s precisely the problem.

They create what researchers call an illusion of mastery.

Why traditional study methods fail

Research consistently shows that:

• Rereading and massed practice (cramming) are the most popular study strategies
• …but they are also among the least effective

Massed studying can lead to higher scores on an immediate test, but the learning fades quickly. In one study cited in the book, students who relied on massed practice forgot nearly 50% of what they had learned just two days later.

By contrast, students who spent the same amount of time practicing retrieval, actively trying to recall information, forgot only 13%.

Even more striking:

• Taking a single test boosted performance by 11% one week later
• Providing feedback on wrong answers strengthened retention even more
• Delaying feedback slightly (instead of giving it immediately) led to better long-term learning, because learners didn’t become dependent on constant correction

The takeaway is simple but powerful:

Learning happens when we interrupt forgetting.

Momentary performance vs. lasting learning

A concept I found particularly relevant for schools is the difference between:

• Momentary strength – how well students perform right now
• Underlying habit strength – how well they can recall and apply knowledge later, under pressure

Dogged repetition, doing the same thing again and again, boosts momentary strength but does little for habit strength. This explains why students can do well on weekly tests, yet struggle to apply concepts months later or in real-world situations.

Ironically, the more something feels easy during practice, the less likely it is to stick.

What actually works: strategies that build long-term memory

Learning science points to several strategies that dramatically improve retention and transfer:

1. Retrieval practice
   Low-stakes quizzes, short writing prompts, or asking students to explain concepts from memory, without notes.
2. Spaced practice
   Revisiting material over time instead of cramming it all at once.
3. Interleaving
   Mixing related topics or problem types, rather than practicing one skill in isolation.
4. Productive struggle
   Letting students attempt to solve problems before being taught the solution—and explaining their thinking.
5. Varied practice
   Changing conditions and contexts so students learn to adapt, not just repeat.

As the book puts it:

The better your mastery, the less frequent the practice should be, but it should never disappear.

Why this matters for Thai education

In Thailand, we invest enormous time and resources in education. Students attend school for long hours, attend tutoring classes, and prepare intensely for exams. Yet employers, universities, and even parents often say the same thing:

Students struggle to think critically, apply knowledge, or retain what they’ve learned.

This is not a student problem.
It’s a learning design problem.

Our classrooms are still heavily oriented toward:

• Coverage over mastery
• Correct answers over thinking processes
• Short-term exam performance over long-term understanding

Learning science suggests that small shifts in classroom practice, not massive reforms, can unlock much better outcomes.

Learning That Shows Up When It Matters Most

Make It Stick actually opens with a powerful story - a pilot is flying alone through the night at eleven thousand feet, on a hotshot freight run to a manufacturing plant in Kentucky. The factory line is shut down, waiting for these parts. Mid-flight, the pilot notices a sudden drop in oil pressure in his right engine.

There is no checklist in front of him.

No instructor.

No time to reread notes.

What matters in that moment is not what he once understood, but what he can retrieve from memory, quickly and accurately, under pressure.

That story captures the true purpose of learning.

Education is not about acquiring knowledge that feels familiar in the moment or performing well on the next test. It is about acquiring knowledge and skills so deeply embedded in memory that they are available when we face new problems, uncertainty, and opportunity.

This is exactly what many of our students struggle with today. They may recognize content in textbooks or exams, but they cannot readily pull it out, connect it, or apply it when situations change.

The opportunity ahead

For educators and school leaders in Thailand, this presents a real opportunity.

By redesigning everyday practices such as:

• In-class writing instead of passive note-taking
• Low-stakes quizzes instead of last-minute reviews
• Labs, projects, and explanations that require recall and reasoning

we can help students make far better use of their effort.

The science is clear.
The tools are practical.
The question is whether we’re willing to let go of what feels effective and start designing learning that actually lasts.