Kids instinctively have this trait yet somewhere along the way as we grow older we forget how important it is to have fun. Why is that? It's not like we don't know how to have fun, life just gets so heavy that we become too weighted down and having fun seems irresponsible. Find some fun in your life it will do you good. If you don't know where to start, be around children and they will guide you. Swing on a swing set. Pull off a prank. Blow bubbles. Hop scotch. Play a game. Whatever it is that you have fond memories of as a child, start there.