Being a famous musician means you are partially locked in to performing the same hits forever. While that would be a nice problem to have, I’m glad it didn’t happen to me; I’m always looking forward, not back.
Many of those people are sorry they wrote some of those songs. They became hits and they have to play them over and over again and didn't really like them in the first place! Better be careful what you write. It may come back to haunt you later!! Granted it is a nice problem to have. Money and fame amplify the person you already are most of the time. If you are level-headed and sane, you most likely will stay that way. I have met some extremely famous and talented people who were very down to earth and "normal". You figure out pretty quickly they are just normal people with a very strange job and life, in that everyone knows who they are and so on.