I’ll always remember what our stats professor told us at the beginning of the semester years ago: “You’ll only remember 5% of what you’re currently learning at university.”
As a teacher now, I must bow to the evidence. The battle against forgetting has no end.
And Ebbinghaus’ famous forgetting curve confirms that. Students typically forget 90% of what they learn in class within 30 days, and most of that forgetting occurs within the first few hours after class.
This has got to be the most depressing fact in education, don’t you think?
Actually, not quite. For two reasons. There are two types of forgetting, and each plays an essential role in learning.
The first type of forgetting is active, and acts as a spam filter. It enables you to prioritize information and focus on what your brain thinks is important.
But what exactly does your brain deem important?
Our brain has evolved to retain info and skills that we need to use over a long period of time. Basically, we’re evolved not to waste a lot of energy learning what’s going to be used only one time. What is considered useless gets filtered out.
So for the brain, repetition means usefulness. Rehearsing and repeating tell your brain not to lose track of that info or skill because you’re going to keep needing it in the future.
This leads to the second type of forgetting, which is passive and referred to as decay. Memory fades with time, and that’s a pain, isn’t it?
But here’s the good news. Dr. Robert Bjork’s New Theory of Disuse shows that forgetting actually increases learning. Memory seems to have a muscle-like property; breaking down promotes rebuilding. This means that without some forgetting, you may get no benefit from further study.
As a peak learner, you should see forgetting as what it really is. It is a filter that blocks the background noise so the right signal can stand out.
You should also make the most of it. You want to remember something for a long time? Space your learning periods. This will enable forgetting to strengthen your learning.