ha I hope to be in your shoes soon, I have a schwinn pro stock se yellow that needs to be built up. I am 26 and road bike race but I love to ride mountain, cruiser, bmx. Also do some questionable manuvers in the downtown area, on road and mountain, but I've never been hassled, people up here too reserved and easy going. Once I get the schwinn built I'll find out.
What you should do is ride the same route later on a road bike and chat with all the same people that flipped their attitude on you. Or just carry some mase.