ShiroKuro Maybe it's like why we do anything for other people, we hope it makes them happy, and we feel good doing something for others?
Yes, and the second part rings true--gift giving often does as much, or more, for the gift-giver than for the giftee. It makes us feel good giving of our own free will.
Thinking about this some more since I posted yesterday, it occurs to me that performing in front of others also satisfies the showman in us (I'm thinking in very general terms and not about anybody here!!). We like our moment in the spotlight and a little bit of praise. This is definitely not to say it's showing off, but rather that most people do appreciate having their egos stroked now and then. For those who don't perform, they get it in other ways.
ShiroKuro, how strong is your need to perform? My teacher performs a lot, in some small things and in some major undertakings. I suspect there is a level of compulsion present in her need to perform. Injury has forced her to cut back some and it is very hard on her.