Separately Gates looks amazingly old in the last few years way beyond his age. Especially in that photo. That is not the skin of a man in his late 50's.

I've speculated that he has either to much sun exposure [1], smokes (but he doesn't?), or has some sickness that has caused him to age.

Actually when he retired from Microsoft I had thought that health might have something to do with it. (I don't remember many cases anecdotal of successful business people "retiring" as early as he has done. They usually continue strong until a ripe age.)

Obviously there is no known sickness that he has spoken publicly about but that wouldn't be that unusual.

[1] But he doesn't seem like the type that would be baking in the sun over the course of many years and he does live in Washington State not in Florida.

Edit: It's not off topic and it's not a comment made for vanity reasons (ie "jeez doesn't he look bad!"). The comment is made primarily because I think he possibly has health issues and I'm curious what others think (especially those on HN with a medical background).