I am a firm believer that age is just a number. An awesome and personal example is that of my grandmother. She is now in her 80s and she swims in the sea every morning, goes for long walks on mountain trails, writes journals daily and has written several books, helps with charity fanatically, and she’s in a choir! People used to tell me, you’re grandma has superwomen skills. But my question is this: Is she keeping her brain young…