Elon uses the “Richard Feynman” technique from what I have read about his approach, mixed with “first principles.”
… which is, basically, in simple terms: don’t try to remember, but try to understand; when you understand, you will remember automatically.
Sounds simple? But yet, so many people don’t do it like that. They try to cram loads of info and facts into their brains, especially students, with the result of forgetting a lot of it.
So how does Elon do it? He is quoted on Reddit:
One bit of advice: it is important to view knowledge as sort of a semantic tree — make sure you understand the fundamental principles, i.e. the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to.
So what Elon basically does is, he looks at the most fundamental principle of any subject matter, instead of separating the subject matter into smaller pieces.
Example: All the A’s are different. But fundamentally they are the same. So he remembers the fundamental first principle. So when you remember the first principle, you remember everything that branches off the first principle.
Obviously, you can now notice that remembering and learning go together. If you’re good at learning, you’re also a natural at remembering. And vice versa.
Also ask “What does this remind me of?” and “Why does it remind me of it?”
“First principles” is not limited to physics. Elon has a tech company and makes tech. If you understand the natural laws of physics, you can use that as a blueprint to make solid tech.
For psychology, first principles would be neuroscience. Or for biology, first principles would be chemistry.
Obviously this won’t give you Elonian-like cognitive abilities. He is from another planet (pun intended). But at least YOU can improve on your memory a bit, and the way you process data.