Yes, absolutely, I do, and not just when writing code. I used to work on retail self-service kiosks, and I'd sometimes have to work in the hardware lab around t

Yes, absolutely, I do, and not just when writing code. I used to work on retail self-service kiosks, and I'd sometimes have to work in the hardware lab around the QA engineers, who for some reason at this company tended to be very perky, gregarious extraverts. They'd see me in there chasing down a bug on one of the kiosks, and invariably they'd ask what's wrong or tell me to cheer up or ask if maybe I'd heard something about the latest round of layoffs. I do it when I play guitar or piano, too. I've had people ask me why I'm angry when I'm playing. My mom did it, too, when she played play piano. I just figure it's because I'm focusing so hard on what I'm doing that I stop concentrating on my expression.