I'm looking for references or anecdotes about writers / researchers / creatives and their need for a quiet and interruption-free working environment
Much as I like y'all's personal stories, I'm probably more interested in someone modestly famous.
Don Knuth's comments on email com to mind:
Email is a wonderful thing for people whose role in life is to be on top of things. But not for me; my role is to be on the bottom of things. What I do takes long hours of studying and uninterruptible concentration. I try to learn certain areas of computer science exhaustively; then I try to digest that knowledge into a form that is accessible to people who don't have time for such study.
Note that it's not merely "uninterrupted", but "uninterruptible" concentration that he requires.