The Forgetting Curve

Lewis Carr looks at why what we learn today is often forgotten by tomorrow.

eLearning is often training that goes in one ear and out the other, like when I ask my kids to put their plates in the sink (for the millionth time).  Learners sit through a mandatory module, pass a quiz, and by next week, most of that knowledge has evaporated. If you’ve ever completed an online course only to forget the content days later, you’ve fallen victim to the infamous “forgetting curve.”

And it’s a big reason why so many training programs fail to create lasting behavioural change on the job. After all, if employees can’t remember the training, how can it change their behaviour or boost productivity?

This isn’t just a learner’s excuse; it’s a real psychological phenomenon. Back in the late 19th century, psychologist Hermann Ebbinghaus conducted some painstaking memory experiments on himself. He memorised lists of nonsense syllables and tested his recall at various intervals, from 20 minutes to 31 days.

The result was a graph shaped like a ski slope: memory retention drops like a rock shortly after learning, then levels off over time. Ebbinghaus dubbed this the ‘Forgetting Curve’.

So how quickly do we forget? Ebbinghaus’s research revealed some eye-opening (and somewhat depressing) numbers. Within 20 minutes of learning something new, a significant chunk is already gone. After one hour, people have forgotten about half the content on average. By 24 hours, we forget roughly 70% of what we learned if we make no effort to retain it.

Keep going, and the curve gets even uglier: one week out, as little as 10–30% of the original information remains in memory. In fact, one study noted that knowledge retention can be a mere 10% a week after training is completed.

So it’s no wonder that employees can barely recall that new policy or software tutorial by the time Monday rolls around again.

Compliance training is the poster child for this issue. Compliance courses are more about covering the company’s ass rather than truly ingraining knowledge.

Employees know it, managers know it. Everyone just wants to get that completion certificate and move on. As a result, the design of these trainings often doesn’t even try to encourage long-term retention, as nobody cares if you remember the material, as long as you ticked the required box.

So what does it matter if employees forget stuff? What’s the big deal? Can’t we just schedule a refresher next year? Well, sadly, that’s what most companies do, they bring it out again and stick a new date on the end of the title (you know who you are!)

Unfortunately, forgetting has some serious consequences for organisations. Lost knowledge = lost productivity. If an employee can’t recall the correct procedure or important information at the moment of need, work slows down or mistakes happen. This is the true cost, and one of the reasons that people don’t truly value their learning platform.

If we look at the bigger picture, the forgetting curve explains a lot of frustrating phenomena. It’s why a one-off workshop rarely leads to lasting workplace change. It’s why employees joke about barely remembering mandatory training moments after it’s over. It even sheds light on everyday life situations. Have you ever forgotten a password a day after creating it, because you never needed to remember it until later? That’s the forgetting curve in action.

Beating the Forgetting Curve: How to Help Learners Remember

Fortunately, the forgetting curve isn’t unbeatable. It’s based on predictable patterns of memory, which means we can counteract it by designing learning that plays offensively.

Let’s look at some research-backed strategies for overcoming the forgetting curve in corporate learning:

Spaced Repetition

Stop trying to cram everything down the throat of your users like you’re at a Pizza Hut Buffet, instead, spread it thinly.

This strategy involves revisiting learning content at intervals, for example, a quick review a day later, then a few days later, then a week, and so on. Each review “reminds” the brain that this knowledge is useful, effectively patching the leaks in that memory bucket.

Make It Active

Pop quiz hotshot! No, really, quiz your learners. It turns out that being tested on information (or having to actively recall it in some way) is not just for grading purposes; it actually strengthens memory. This is known as the testing effect: every time learners have to retrieve knowledge from their brain (even if they struggle), it solidifies that knowledge further.

Learning Nuggets

Thanks to TikTok and its pals, we live in a world of short attention spans. Rather than fighting that, leverage it. Microlearning involves delivering training in bite-sized chunks – say 5-10 minute modules or even daily one-minute tips. Learners are far more likely to engage with a short module regularly than a daunting 3-hour course. And by spacing these nuggets out, you naturally build reinforcement in.

Relevant & Meaningful

One surefire way to have learners forget something is to teach them something that feels utterly irrelevant to their job or life. (Remember memorising obscure math formulas you never used again? Exactly.) To strengthen memory, make the learning content meaningful and contextually relevant for your audience. In Ebbinghaus’s terms, this increases the “strength of the memory”.

By combining these strategies, we essentially transform the learning experience into something where learners actually remember what we need them to, and they apply it on the job, leading to the performance boost and behaviour change we originally hoped for.

It’s worth highlighting a shift in mindset for L&D teams: to truly combat the forgetting curve, we must move away from the “check box” mentality and toward a “change the behaviour” approach. This means success isn’t completing a course; success is seeing people use that knowledge when it counts. Compliance training will always be required, but even there, we can infuse practices to help retention (and maybe even make it less of a chore). For instance, instead of the endless yearly click-throughs, some organisations now use pre-assessment strategies: let learners test out of what they already know (to save everyone’s time) and focus training only on what they don’t know.

Others are turning compliance topics into ongoing campaigns rather than annual rituals, so that important principles are refreshed throughout the year rather than forgotten 364 days at a time. When learners see that the company actually wants them to learn and not just tick a checkbox, engagement goes up, and forgetting goes down. For broader professional skills and staff development, treating learning as a continuous journey is key. Maybe that means turning a workshop into a series of events with activities in between, or following up an eLearning module with an assignment or discussion forum. It can help to imagine what you’d do if your job performance depended on people remembering the training (because honestly, it does). You’d likely chase people down with reminders, coach them on the job, send them quick tips and quiz them lightly to keep them sharp.

It’s a bit like being a personal trainer for memory: you don’t just show the client how to do an exercise once and then vanish; you develop a workout routine over time.

As L&D professionals, we need to be that coach, designing the “exercise regimen” that follows the initial lesson. One more real-world example on doing it right: Choice Hotels’ learning team noticed that after launching a new training, employee engagement with that content plummeted 30 days later (no surprise, the forgetting curve strikes again). And their data showed that hotels where staff kept up with ongoing learning had better business outcomes.

So they piloted a reinforcement strategy – providing bite-sized follow-up lessons and resources over time after the main training. Learners returned regularly for these reinforcement modules (voluntarily!), and the company saw a 32–64% boost in engagement with the training content compared to content that wasn’t reinforced.

In other words, people learned better and actually liked it enough to come back. The continuous approach cultivated a real learning habit, which is the ultimate antidote to forgetting. While not every organisation has a fancy LMS feature for automated spaced reinforcement, the principle stands: make learning a habit, not a one-hit wonder.

Lewis Carr Founder. Moodle Wizard. Digital Nomad. Lewis wears many hats but his most comfortable is his Dirtyword beanie. Connect wth him here: https://www.linkedin.com/in/ lewiscarrlearning/