The forgetting curve

The Forgetting Curve

Think back to a time when you studied for a big exam. How much of what you learned could you recall 1 week after the exam? If you are anything like me, not much.

For most of my life, my strategy for passing exams or giving major presentations has been to lock myself away and rehearse furiously in the days leading up to the event. I cram as much information as possible in my brain and practice recalling until it sticks. I then go on autopilot and regurgitate it (pretty much) verbatim on the day.

For me, this has been an effective strategy for passing exams or giving one-off keynote speeches. However, it is a lousy strategy for remembering content over the long term. One week later, my brain has moved on to new things, and my short-term memory purges most of what I crammed in there.

Hermann Ebbinghaus described this phenomenon as The Forgetting Curve (also known as the Ebbinghaus Forgetting Curve). It represents the decline in memory retention we experience over time if no attempt is made to retain the information

Think about the last webinar or training workshop you attended. According to Ebbinghaus, 1 hour after the talk is over, you will probably only remember 50% of what you learned. 1 week later, you remember just 20%. That’s why one-off learning events are terrible for long-term recall. Spaced repetition is the key to retaining knowledge (see the image below).

the forgetting curve

Ebbinghaus found that every time you reinforce and practice what you learn, the rate of memory decline reduces. He also found that you retain information better when you get actively involved vs. just being a passive observer.

The medical profession knows this. Surgeons have a saying, “See one. Do one. Teach one.” After observing a surgical procedure, trainee surgeons practice “doing” that procedure. Then, to fully cement the knowledge, they are expected to teach another trainee how to conduct the procedure.

My takeaway: Whenever I learn something new, I try to put it into practice and “do one” as soon as possible. I also try to teach the concept to someone else in my own words. (In case you hadn’t noticed, that’s what this blog is all about)


Footnote: I returned to New Zealand in 2020 after living in North America for 12 years. Back when I was in the USA I saw a big-name business guru speak at 3 different live events in the space of a year. The 1st time I saw him, I thought he might be the most skilled presenter I have ever seen.

But by the 2nd and 3rd times, I realized his presentation was exactly the same each time. Word perfect, the same jokes, the same gestures, the same pauses. It was like watching a replay of the same movie. It dawned on me that he wasn’t “cramming” his presentation as I do in the days leading up to an event. Giving the exact same speech every week was his “job”, and he honed it to a fine art through spaced repetition.

So I sat back and studied the clever persuasion techniques and rhetorical devices he used to present his opinions as if they were facts. Most of the audience lapped up the information unquestioningly. Personally, I think most of what he says is BS. And the more I learned about the guy, the more I realized that what you see on stage is all there is. Scratch below the surface and there’s not a lot going on below his polished veneer. But what an amazing presenter. And he makes a fortune. Good for him!

Until next time…