This is a great list. I think it's too easy to focus on will power alone.

I've been training myself for years to be able to work longer hours. I've built up to the point where I can work for 12-16 hours straight, everyday. Unfortunately I'm only now realizing the extent of other costs. During weeks or months when I'm working hard, I have begun to notice many things:

• I find it much harder to remain completely calm and respectful while interacting with people close to me. (I used to pride myself on my levelheadedness in interpersonal relationships)
• I find myself physically tense. I have to consciously relax muscles, especially facial muscles. (I used to pride myself on being very relaxed, physically and emotionally)
• I'm much more neurotic, and frequently lose sleep analyzing whatever problem I'm working on.
• Thoughts of opportunity cost are ever prevalent, and wear me out emotionally.

I've been trying to develop a personal philosophy in contrast to Eliezer's Extraordinary Effort idea that stresses not having an emotional stake in what I work on, especially if I work on it 12 hours a day (I call it Directed Apathy). I've had some mild success but in the end it may be that I just need to work less in order to stay sane.