I'm similar to OP in that I like to be left alone when I'm out. Can't even be arsed with "banter" really, I just don't like having conversations with people I don't know when I've got shit to do. So it's a rare day I'll wear a City shirt when I'm not planning on going to a game. Still not forgotten the morning after the Champions League final though when I went out in my shirt to Tesco - as soon as I got out the car some United fan drove past me shouting "You've got shit in your shirt mate!" Didn't even look at him cos I was walking on air. Still can't be arsed, though. When I'm out in Manchester itself I'll chance it cos City shirts are dime a dozen in town but out in the suburbs where I live I'm within a mile of Stockport's ground and 50% of their fanbase are United first.