These days I write more than I code, but one of the things I miss about programming is the coder's high: those times when, for hours on end, I would lock my vision straight at the computer screen, trance out, and become a human-machine hybrid zipping through the virtual architecture that my co-workers and I were building. Hunger, thirst, sleepiness, and even pain all faded away while I was staring at the screen, thinking and typing, until I'd reach the point of exhaustion and it would come crashing down on me.
It was good for me, too. Coding had a smoothing, calming effect on my psyche, what I imagine meditation does to you if you master it.