Same here. Between 11pm - 4am. I'm not sure why, but I just feel much less distracted at night. Maybe it's the feeling that it's calm everywhere or maybe because daytime at office, with low cubicles, is full of noise and movement. Even with my noise-canceling headphones, I can never escape the feeling of movement and noise around me.
Sometimes, I sneak into an empty conference room when I've to really focus during the day.
> Even with my noise-canceling headphones, I can never escape the feeling of movement and noise around me.
If you are anything like me, the root cause may not be the noise and movement. It may instead be the anticipation that the noise and movement is someone who is about to pull you out of your flow. Even if it doesn't happen that often, the psychological jolt that occurs every time it does is enough to make my mind resist concentrating when potential distractions are around. Noise-canceling headphones do nothing against a tap on the shoulder.
"The mere possibility of being interrupted deters hackers from starting hard projects. This is why they tend to work late at night, and why it's next to impossible to write great software in a cubicle (except late at night)."
From, you guessed it, Paul Graham... (Specifically, footnote #1 of chapter 6 of Hackers and Painters, aka "How to Make Wealth" http://www.paulgraham.com/wealth.html#f1n)
Ya, I think that's what I fear as well. I get into a sort of tunnel vision when I'm focused. Some of my colleagues have mentioned that they have stood at my side for a minute or so(I have a slight reputation ;) ) and I don't feel that there is anybody there. When they finally do tap, it's all the more jarring.
I'm well known for jumping about a foot in the air when tapped on the shoulder. I despise workspaces where people can walk in behind me. (Hello cubicle!) When I'm in the flow though...
Aggh, I'm getting paranoid just thinking about someone walking in behind me now. Working when nobody else is around and no phones can ring is the best kind of work.
Sometimes, I sneak into an empty conference room when I've to really focus during the day.