Graduate school.
About the same time as I began commuting on a thirdhand hybrid, a few friends and I were talking about what we did to stay sane during the years and years of the PhD. Everyone had really extreme hobbies, like running marathons, working as a gourmet chef, serving as a minister, and so on.
I did a lot of little things, but nothing in a big way. But I was getting into cycling and mechanical work, and so I saved up for a while, hung around the LBS and learned what I could, and finally got it together and decided that TransAmerica was my goal.
I'm not there yet, but I'm on target for doing it the same year as I finish my degree and get a job. The three feed off each other and keep me going when each one might become a grind alone.