50 isn’t old…there’s a lot of time and energy left to commit to something new.
The Second Saturn Return brings with it an awareness of mortality. Saturn slows you down and forces you to take a long hard look at reality. How much time do you have left? How do you want to spend it? There really is no time left for procrastination, otherwise time will be up and those books will never be written or paintings painted. Ironically as the remaining time diminishes, subjectively it passes with ever increasing speed.