The one most dependable thing you can do to add years to your life is to curate a circle friends, four or five friends, who A) you can count on. But that also means you have to be willing to be counted on on their bad days. People whose idea of recreation is walking or golfing or playing tennis. People, quite honestly, who eat a plant-based diet. You should have one or two vegetarians in your immediate social network. And people who will keep your mind challenged.