As spry as he was until the end, we’re betting Leonard would agree with this one: Want to feel younger? Act younger in a meaningful way. Your mindset has a lot to do with how you age. “How old we feel—our subjective age—can influence how we age. Where age is concerned, the pages torn off a calendar do not tell the whole story. … subjective age correlates with certain physiological markers of aging, such as grip strength, walking speed, lung capacity, and even the levels of C-reactive protein in the blood, an indication of inflammation in the body. The younger you feel you are, the better are these indicators of age and health: You walk faster, have better grip strength and lung capacity, and less inflammation.” Why You Can’t Help But Act Your Age by Anil Ananthaswamy for Nautilus is a tour de force, combining the best of science and health writing with some simple, practical facts that could change how you view getting older, whether you’re reading this in your 20s or your 70s.