You can switch fun to whatever you find meaningful or whatever you want to optimize for. Optimizing for longevity is one option, but you would never go full in

You can switch fun to whatever you find meaningful or whatever you want to optimize for. Optimizing for longevity is one option, but you would never go full in on it (would you kill an innocent child to live one second longer?). So why would it be surprising that weight assigned to it varies among different people? Btw I agree with him, I think that's what you really want, but you want your fun. Not fun as perceived by other people. It does not necessarily mean pleasure.