For many years I was known as a workaholic, but I really enjoyed the work and sometimes I wrote code for 14 hours a day simply because I was having so much fun. But then I suffered an episode of burnout. I tried many things to cure it: I took a long vacation, but that did not help. I got really into jogging, and started running 20k comfortably, but that did not help. I tried antidepressants, but that did not help. My friends kept suggesting herbs to me, so I think I tried something like 20 different herbs, none of which help. On the theory that I'd been sleep deprived, I started sleeping 10 hours everyday, but that did not help. I read some good books, watched some good movies, and tried to let myself relax a bit, but that did not help. Nothing helped until I saw a sports doctor who suggested I take testosterone to help me stay in shape. So I took testosterone and the burnout was cured within 2 weeks. Suddenly I could write code for 12 straight hours and really enjoy it again. My ability to concentrate was incredible. In retrospect, it seems clear, the burnout was because my brain wasn't getting enough testosterone, which apparently kept me from feeling excited about work.