As we get older, learning something new becomes more complex, tedious, and time-consuming than ever, and those child geniuses who can speak five different languages become our favourite dinnertime conversation, because how do they even do that?

But mastering unfamiliar subjects, whether you’re still in school or not, doesn’t have to be so painful. Take it from Nobel Prize-winning physicist, Richard Feynman. He stumbled on a three-step formula that makes you learn anything not just faster, but on a deeper level too.

As Shane Parrish explains over at Medium, Richard Feynman exemplified the difference between "knowing something" and "knowing the name of something".

What does that mean? Feynman explained it once in an interview, saying that someone could show you a little golden-breasted bird, and tell you it’s a brown-throated thrush. They could tell you it’s called a halzenfugel in German, and the Chinese call it a chung ling.

You could remember these facts for the rest of your life, but you’d still know nothing about the actual bird - where it lives, how it migrates, what its calls sound like.

That’s a really obvious example of Feynman’s point, but it applies to far more complex subjects too.

Take water conducting electricity - it’s a fundamental part of how we understand the world around us, but after 200 years of searching, scientists have only just figured out how it actually happens.

A deep understanding of a new subject is crucial - even if you’re just trying to make it through an exam, because you have no idea what aspect of that subject they’re going to probe you on.

So get ready to 'learn how to learn' from a legit genius using the Feynman Technique.

Step 1: Teach it to a Child

Get a notebook out, write the topic you’re learning at the top of the page, and explain it, from start to finish, as if you were explaining it to a child.

If your first response is, "Um, how do I explain quantum mechanics to a child?" remember that xkcd once explained rocket science using only the 1,000 most common words in the English language.

That’s the key here - when you’re writing out your explanation for an eight-year-old, you can’t hide behind complicated jargon that you don’t actually understand.

"When you write out an idea from start to finish in simple language that a child can understand (tip: use only the most common words), you force yourself to understand the concept at a deeper level and simplify relationships and connections between ideas," says Parrish.

"If you struggle, you have a clear understanding of where you have some gaps."

Step 2: Review your knowledge gaps

Now that you’ve identified the gaps in your knowledge, you can study those specifically, get the answers, and repeat Step 1. Keep doing this until there are no gaps at all.

Step 3: Organise and simplify

You now should have a complete explanation for your new subject, that’s simple and comprehensive enough that even a kid could follow it.

Try to boil this down and simplify it, and read it out loud - that will help you identify any shaky, unconvincing bits.

Step 4 (optional): Try it on an actual human

You could recruit an actual eight-year-old and try explaining it to them, but assuming there’ll be attention span issues, grab a friend and try it on them.

If they don’t understand something in your explanation and you can’t explain it - there’s another gap.

And that's all there is to the Feynman Technique.

It's no quick fix (spoiler: there isn't one), you still have to do your study, but if you do it right, you're guaranteed to have a deep understanding of the subject you're trying to learn, and it's not all going to fall out of your head the minute you leave the exam hall.

Check out the video below to see the technique in action: