That we should -- that we should all be hungry for a lifetime. I mean, for example, at my next birthday I'll be 68.

All the great scientific discoveries made by all the great geniuses were largely made

when they were in their 20s and 30s. And yet I became, about two years ago, obsessed

with particle physics and I was determined to understand it before I died.

I could not have done that if I hadn't learned to read when I was young. If I hadn't had the opportunity

to study science courses in my high school, and I lived in the second poorest state in the United States,

which most people my age in my state did not have.

I happened to go to a bigger high school with people who

understood we had to get good science and math teachers there.

And if I hadn't gone to, in my case, Georgetown University, which was a Jesuit University,

and I hadn't been subject to the kind of rigors that the Jesuits imposed which made me realize

that however much I thought I knew and however smart I was I didn't know very much and I

wasn't very smart. I had a lot to learn.

So that's the most important thing I learned, that your brain is a gift.

And we now know that people well into their late 60s and 70s can form new neural networks.

So that even though your brain begins to shrink in your 30s, and does throughout your life,

since none of us ever use even close to half of our brainpower we got a lot left.

And we will on our last day on earth we'll have a lot left.

So, the idea that we now know, as a scientific measure because of all the brain scanning

technology that we can form these networks and that we form them best, we're most likely

to form new neural networks later in life by learning something new.

So if -- I said I was interested in particle physics and also in astrophysics and I'm trying to figure out

what it means that we've located 20 planets outside our solar system in the last five years

that seem to have enough density and be far enough away from their suns that they

might be able to support life. That may be the answer to the Russia Ukraine problem;

an attack from outer space will immediately unite us all.

Members of Congress in the U.S. will immediately start hugging each other and singing Kumbaya.

But anyway, I can form new neural networks doing that because I don't know anything about it,

or I didn't when I started. A theoretical physicist would do better going to Suzuki

piano lessons with his grandchild or her grandchild and just playing if you knew nothing about music.

But this is an incredible thing that the most important thing I learned is that

it's important to keep on learning. That you should stay hungry and that the greatest gift

can be even as your body begins to fail if your mind's still working you need to use it.