how to live longer

Call it unrealistic optimism, but my game plan for growing old gracefully is to stay as immature as possible. I don't mean that I'll hang on to my weakness for stupid jokes or certain video games (although I'm not ruling out puns and Mario Kart at age 80, if I can still manage them).
Switzerland has one of the highest life expectancies in the world.
His answer caught me by surprise. I almost knew he'd say something like eating the food you grow, or taking care of your digestive system, or something along those lines.