What made me want to play guitar was that painting of Wings in concert in the gatefold of Wings Over America. It looked so exciting... I wanted to be part of it.
I think for many songwriter/performers, you need to go off by yourself and write the songs to begin with, but then you need people to bring them to life. So you have to be comfortable with solitude and also with being very social.
For some musicians it becomes self-reflexive to think, "I have to write some of my kind of songs now."