Derek Thompson

I think I would have assumed the opposite, that memory might slowly drop off in one's 20s and 30s.

And then maybe in our 70s and 80s, there's like a sudden acceleration downward.

But I can see you're shaking your head.

No, that's not what you found.

That's really interesting.

Yeah, this would explain why my wife has pointed out that at 39, I seem to have much worse memory than I did at 29.

You got it.

We have a child.

We have a home.

We have complicated jobs.

This is actually wonderful.

I now realize that I have a biomedical excuse that I can give to my wife every time she tells me I'm terrible at logistics.

It's not my memory so much that's slipping, although it might be slipping a little bit.

It's that my life is much more complex.

We're gonna get to your most recent study, your blockbuster study in just a few minutes, but just one more question here to sort of set the stage for this piece of research.

You have these tests that are measuring memory, and memory is kind of an external validity test.

It's how memory is presented in the world.

When we look inside of people's brains, especially the brains of older people who we know had Alzheimer's or dementia, or maybe just quote-unquote average memory loss,

What are we seeing?

Is it a loss of brain mass?