First of all thank you for acknowledging the reality of flow; I've had a lot of methodology-believers tell me that
* flow is a myth. Since they have never been allowed (or able) to concentrate, they don't think anyone else has either
* people who want to work alone or who want to focus instead of socializing and pair programming are antisocial if not mentally ill.
Now about that daily scrum. First of all maybe it's supposed to be fifteen minutes but I've never seen that. half hour to an hour is a lot more common and most of that time is spent in discussions of no use to most attendees.
As for it being at the beginning or end of the day, I have never seen anything but the beginning of the day, and at an inhumanly early hour. I was working in Seattle; I awoke around 9:00. left the house at 9:30, got to work at 10:00 I waited until the rush hour traffic was over.
With a (useless) 8:30 meeting to attend I had to leave the house at 7:00, awakening at an hour I never got used to, and arrive after a 90 minute drive that was mostly at walking speed. So I had an extra unpaid hour and arrived weary and angry, not something I could just turn off after hearing the people, who were in the same group but whom I didn't work with, intoning wearily that they were working on the same thing as yesterday.
It was an absolutely horrible way to start the day, and while I arrived already in a bad mood from the commute, it got worse during the meeting what with the Agile Newspeak of "stories" and all that, which I despised. And then there were the PMs, who I knew for a fact played games on Facebook all day, perkily spraying one buzzword after another to put on an appearance of being "engaged."
Try getting into flow after a day that begins like that.
Sprints? Sprints, you say? How many meetings are part of each one? A planning session, OK, but it should be based on a design document. But then there are extra meetings during the damned thing and a "retrospective" at the end that would have driven me right the fuck out of my mind.
And the whole point is not to divide the project into milestones (we've always done that) but to keep the pressure on; we have a two-week deadline, we're always behind, thereby creating an excuse to keep us working 60-80 hours a week.
I remember private offices and working alone. One meeting a week and the only process was the checkin system, which at Microsoft became the biggest impediment to our work.
No matter to me; I only work remotely and at 66 I can quit anytime I want. But I will never do agile or scrum or TDD. And lately I'm doing as much technical writing as coding, There are no fads in technical writing.