Stand-up comedian Jerry Seinfeld mentioned in an interview that he still goes to comedy clubs to perform every week. Obviously he isn't doing it for the money. It's the process of testing out meterials before big shows that makes him good at his acts.
My takeaway from such stories is that Passion for work and keeping in touch with the path that lead them to success helps them stay relevant and successful.
BTW, comedians literally call this "working out"—it's understood that if you don't use it, even for a week, you start to lose it. So along with a need to do it, part of it is that it's more difficult to get back into comedic shape than it is to stay in shape.
I bet it does. It's just that most programmers are used to working at 25% or less of their actual capacity due to constant interruptions, so it's less apparent.
He talks about this in the Comedians in cars getting coffee Obama episode (worth a watch!). He basically says he fell in love with the work and that’s what keeps him grounded.
My takeaway from such stories is that Passion for work and keeping in touch with the path that lead them to success helps them stay relevant and successful.