Good coding is half art, 1/2 science. During creative periods I can go on coding for hours with out even realizing it. When I work like that, I easily go through the night pulling the "midnight oil". The only difference between now (at 50) and then, is the recovery time from the all nighter. Lately I tend to be less motivated to do it so often.
Absolutely, I always refer to coding as 'creative logic'. :) The Art of Happiness At Work by the Dalai Lama and Howard Cutler is a great book. It talks about flow/being in the zone and after reading about that, I've really felt lucky to have experienced that mode of pure focus and true moment oriented existence.
I was never a person that stayed up all night coding, though. I'm a morning person and my body/mind were always like "no way". But, that being said, I have woken up many times at 3 or 4 and cranked all the way through until 7 or 8 that night. So I think it just depends on your natural biorhythms.
I'm not 50 yet, but already am finding it harder and harder to get a 'good day' of coding in with a wife and 8mo old son. Besides distractions galore, my next big loss is sleep. I definitely feel that side and I'm even having a hard time sometimes remembering things in conversation. I think of it as not having my ECC ram. :)
However, like many other postings, I will probably code until I die or until I just can't understand anything anymore. Then I'll probably just back to my 8-bit machines and assembly; the days when things were simpler. The quintessential old man out of step. Heh.
