"Age is an issue of mind over matter. If you…

"Age is an issue of mind over matter. If you don't mind, it doesn't matter." This 1 of wisdom, often attributed to Mark Twain, has been turned into many an 2 internet meme over the years. As a 51-year-old who is starting to feel the gathering momentum of the inevitable slide, it strikes me as little more than a platitude that makes people feel better about getting old. But according to a growing body of research, there is more to it than that. Subjective age - how old we feel - has a very real impact on health and 3. People who feel younger than their years often actually are, in terms of how long they have left to live. The question of what controls our subjective age, and whether we can change it, has always been tricky to 4 scientifically.