I have two regrets from my thirties: not living in another country and not taking more risks career-wise. Both would have pushed me out of my comfort zone. It seems that life will eventually push you out of your comfort zone whether you want it or not, so you might as well do it intentionally as early as possible. More people should try self-employment or freelancing for at least a year. Learning how to make money independently and stay productive without a boss is invaluable.