> I usually get this after-disco/cinema low when the amount of people in office starts to slow down
When the office slows down and things get quieter is when I find myself finally able to get completely focused in on things that require all of my attention.
I enjoy meetings, business talk, planning and miscellaneous conversations with coworkers more than (I think) most software developers, but to get any sizable software project done I do best with chunks of a few hours at a time to get into a focused state, get all of the moving parts loaded into my head, then actually write the code/fix the bug etc.
My solution to this–in an office that I share with people who talk on the phone–is to show up in the late morning after they've made their morning calls, and leave in the evening a few hours after they leave. This way we overlap in the afternoon, but I get some time with a quiet office where I can really think.
Just while writing this comment several conversations happened around me that drew my attention away from what I was writing. When I focused my attention back to the comment, I had to skim what I'd just written to 'reload' my thoughts. At least for me, this 'reloading' process takes a long time when it comes to writing software, despite various tricks I've come up with over the years to help speed it up.