There is one rule for politicians all over the world: Don't say in Power what you say in opposition; if you do, you only have to carry out what the other fellows have found impossible.
Sometimes it's a character you want to play or a story you want to tell. Sometimes it's just to pay the bills.
My mother also had us take piano lessons, and this had a similar effect. I hated those lessons, but I now play regularly for pleasure and have even tried my hand at composing.