Recently finished Peter Attia’s book, Outlive. Lots of good insight and guidance throughout, but I keep thinking about the final paragraph:

“I think people get old when they stop thinking about the future…if you want to find someone’s true age, listen to them. If they talk about the past and they talk about all the things that happened that they did, they’ve gotten old. If they think about their dreams, their aspirations, what they’re still looking forward to—they’re young.”