places/times when it's best not to knit?

[gotta knit]

I have to remake 2 sleeves, since the 2nd one was coming out quite a bit tighter (& smaller). Just realized that most of it was worked on while waiting at a dental clinic, and this week since my dental surgery. (Surgeon actually commented that I was so relaxed I could knit before going in, I told him I was trying to stay calm. Obviously I was wrong.)

What places have you discovered not conducive to good knitting?