This post inspired me to write a reply which I made into it's separate post at http://tumblr.sriramk.com/post/14419136146/on-carmack-and-cu...
Copy-pasted below
"John Carmack is one of my heroes in the tech world. Not because of his technical accomplishments and helping to create games that I’ve spent years of my life on. But for his single minded obsession with his craft after two decades. Every time he is on stage, he is so obviously in love with what he does that it is infectious.
That was one of my favorite things about Dave Cutler back at Microsoft.
Here’s this legendary figure pushing 70 years who has accomplished more things than most developers dream up. But he showed up at work every single day and made checkins every single day - including Dec 25th and Jan 1st, something he was proud of.
I was once at Microsoft campus late on a Sunday and walked past his office. Spotting the familiar blue hue from his office, I looked inside and saw him debugging something.
“Hey Dave,”, I said “Ever get bored of ntos and ntos/ke? You’ve been coding there for…for like 20 years now?”
ntos is the core part of the Windows NT source tree and ke is where the kernel code lives in. Where pretty much every source file would have a header with Cutler’s name on it and a created date in the 80s.
He turned slowly, looked me over. Obviously not very thrilled about this pipsqueak program manager interrupting him being in the ‘zone’. He then smiled and said. “I love this stuff. What else do you want me to do? Be on a boat somewhere?”
With that, he turned back to his debugger and went back to work. "