In the daily search for interesting blog fodder, I’ve come across a lot of advice about how students can best learn and retain information. But one particular approach stood out. It’s so advanced that it’s named after a Nobel Prize winner in physics. It’s so simple that any student can use it. And it’s so effective that I not only wish I’d known about it back when I was a student, but I also use it today whenever I’m trying to wrap my head around something unfamiliar.

Lesson #28 of my final 31 posts: The best way to learn something is to teach it.

When I think of all the study hours my high school and college-age self spent reviewing, studying, and reviewing again only to have the material a) still not fully sink in, or b) seemingly sink in only to evaporate in the first minute of an exam, I can’t believe I didn’t discover this learning gem sooner.

Whether you’re taking in a new idea for the first time or studying past material to prepare for an exam, the single best way to not just recall, but deeply understand whatever you’re trying to learn is to teach it. Out loud. As if you were standing in front of a class (this technique does not require the use of a live audience).

Named after Richard Feynman, a Nobel Prize Winning Physicist, you can find a great explanation of the “Feynman Technique” here from study skills author Scott Young (who learned all the material for MIT’s 4-year computer degree in one year, and did so online). But here are the most important steps if you want this to work.

1. Actively imagine that you’re preparing for a lecture in front of a class full of students who are unfamiliar with the topic. How would you best explain it so they could understand it? That thinking is forcing your mind to work in a way that it doesn’t if you’re just reviewing notes. It’s not necessarily easy to do. And that’s the point. Anything you don’t truly understand, including subtle connections between topics, exposes itself in a way that passive studying does not. You wouldn’t get up in front of the room unless you knew exactly what you were talking about. And this preparation gets the same real result without the real crowd

2. Actually stand up and deliver your lecture, without notes, to an imaginary crowd. You don’t have to project like a crazy person. But if you don’t actually act out the lecture, it’s too easy to accidentally let yourself off the hook in those portions where you haven’t yet made the necessary connections. And once you can nail the lecture, that material is locked away in your memory.

You can spend hours passively reviewing notes and actually not remember any of it. Spending that time actually working through problem sets is a much more active and effective approach. But if you can stand up and teach that material, step-by-step, that’s when you really understand and remember it.

Counselors and other working professionals can use this method, too. Maybe you’re trying to learn how to best pitch your project, or sell a solution, or use a new system? Try explaining it to an imaginary room and you’ll see the learning pick up quickly. I’ve even used it when trying to understand a non-fiction book.

The truth is that my high school self may have rolled his eyes at this suggestion. But students, don’t mock it until you try it. I promise this works.