I know this older guy at my gym — I call him “The Professor,” mostly because he used to teach journalism, but also because it’s more fun to say and easier to remember than his actual name. He’s 85 now, and he says if he doesn’t get to the club to swim laps and sit in the steam room at least three times a week, he feels like he’s doing something wrong. He says he feels the same way about flu shots and all vaccinations for that matter.