A life lesson for me is, how do you muster the courage to take on a new risk? Whether it's starting up a business or taking on a new project or expedition. I think the risks that we take are all relative to the risk-taker.
Writing is so wrapped up in ego, but with math one is just trying to get it right, although you're often wrong. I think math helped me become a good critic of myself, come at writing a little less personally.

