When I was a teenager I wanted to be a mate on a fishing boat. Alas, I was too young to get working papers and went on to college, getting a PhD and becoming a mathematics professor at a Midwestern university. The late '60s and early '70s were exciting times, and I learned the hard way about political correctness. I then had the opportunity to do art and discovered being a starving artist may be nice in theory but not much fun in practice. I got lucky and eventually found a job with Big Blue (IBM) and kept thinking over the next twenty-three years that I'd find the time and the energy to get back to mathematics or art. Not a chance! Retirement provided leisure to write. I never realized how much work is involved nor the number of rewrites necessary before a book is ready for print! For fun I teach yoga, swim, sweat in a sauna, and in the summer run white water rivers in northern Wisconsin with my son. I try to attend as many chamber music recitals as I can in Milwaukee where I reside. Meanwhile my wife and beagle are still trying to house-break me.
Mathematics, art and writing have a lot in common: in the intrinsic nature of the beasts as well as the subjective state the challenges present. In all three, and I'd speculate the same is true for music, creativity is needed to find an interesting question and worry it down to a manageable state. Then the fun begins – can you come up with an answer that another mathematician, reader, viewer or listener would also find interesting and enjoyable? And can the solution stand alone and be heard with at least the fullness the author had in mind -- better yet, can it stimulate unanticipated joy or further challenges? On the subjective side of creation: I can only attest that my mind comes into the same space whether I was doing mathematical research, working with clay or metal and now writing.