Usually isn't a good programmer only. (But has multiple skills)
Has a lot of hidden material/knowledge not written in his CV or told you in a first meeting
Is organized very well (I would go so far to say, that he has is own way [of Dave Allen's] GTD)
Is intelligent and has a good memory.
Is healthy. You can't give 100% without being healthy (in common terms)! There are exceptions: Beethoven was still productive while being deaf. Evelyn Glennie [80% deaf since age of 12])... Lunatics? Madness mostly is very diverting.
Works (mostly) for passion and not for money.
Chooses and isn't chosen.
Can switch between open mindedness and single-task-focus-only very fast.
Adapts his environment to himself and not himself to the environment.
Is entitled as being a strange guy by his co-workers often.
Crap.
Does read on lists, though there are lines with crap because the most beautiful treasures are often found at the bottom of a lot of crap.;)