And no amount of good doctors can make you change your lifestyle. At the end of the day, a ton of doctor advise is ways to change your lifestyle, and that takes personal effort.

Buffet, famously, is known for not having great dietary habits. I agree with you, but he’s not a good example here.

I think he's actually a great example: it's much more complicated than good dietary habits!

Buffett has never been a drinker. It's possible that abstaining from alcohol is the most important dietary habit

He's a perfectly fine example. I didn't suggest he had habits he changed.

Strong sense of purpose?