I did a solo gig in a church in Birmingham city centre last year, it was a Friday lunchtime, part of a regular series, so there's always a good audience, people on their lunch break etc.
I was sat on a stool at the front, people were sat on seats, the closest row about 4 metres from me.
For one guy that wasn't close enough, he walked up and stood literally half a metre from me. After I'd finished one piece, he started talking to me about what I was fldoing and my music etc. Really nice and I appreciated him liking what I was doing, but he was just oblivious to the fact I was performing.