What does fun mean to you?
F-U-N. Such a "fun" word, but what does fun mean to you? Once you define fun to you, it's essential to make sure you are doing what you describe as fun at least once a week. So many of us consume ourselves with working and staying busy. However, business is not being productive or wise; it's just stupidly wasting our bandwidth. Have fun and remember busy does not mean productive.
The question above might be a simple question for you, and that’s wonderful. Simple questions are easier to answer. Take a few minutes to write out all the activities that you define as fun. Once you have completed that, write out all the internal (psychological, emotional and physiological) traits that let you know you are experiencing fun. When you write this list down on paper what you are doing is growing your self-awareness. Life is short. Why waste time pretending you are having fun during your allotted fun time when you are not?