The phenomenology of making art and doing math are pretty different, but the lifetime trajectories of our output in these areas might not be. In both fields, when we look in as outsiders to some particular body of work, we tend to see the semi-magical work of geniuses who we don't think we could ever be... but my experience brushing up against artists and mathematicians suggest that they both attain creative productivity through similar processes. Before producing really creative work, they have to get enough experience with their tools that they can say what they mean to without having to think much about it - they just paint, or just shuffle symbols on a page, and it gets them where they want to go. It makes sense that lots of people would only arrive at that kind of fluency later in life.