26 years ago I was interviewing for a sysadmin job in an academic setting. And I was invited to my prospective coworker's office. He was a software developer, mostly, but jack-of-all-trades for the office systems. There was a lot of data processing involved.

His office featured a Sun workstation on his desktop, and a desk piled rather high with paperwork and whatnot. There was absolutely no wall clock anywhere to be found. His workstation's desktop also did not feature a clock. There was really no indication of the passage of time in that space.

I drank in the import of this, and I asked him if it was true, and he agreed readily. I was sort of amazed. But it was also quite humbling that he could construct such a space, where he could basically throw himself into his work and dedicate as much time as necessary, until his stomach or fatigue drew him back into the real world.