Interrupted while at work

So, I was writing on a pad of paper the other day and someone asked me, "Are you writing a new book?" I kind of sighed and responded with no.

I suppose I appreciate the curiosity, yet it's also common courtesy to not interrupt someone while they're working. If I had been in the midst of writing a book, chances are I'd be in a certain mindset - in the writing zone so to speak - and an interruption like that would completely disrupt that. I'd then have to try and reattain that particular focus and mindset I had possessed prior to being interrupted.

This isn't the first such occasion this has happened and it likely won't be the last. I can understand a person observing another working and wondering, "What is it they're doing exactly?" yet can't that question wait until the person appears to be on break? If a band is in the recording studio, playing a song, the last thing they want to have happen is to be interrupted by someone, asking the question, "Is this a new song?" Why? Because they'll have to start all over again, try to get in a certain mindset and outdo their most recent performance before the interruption.