I've been changing my own flats since I was 12 and had a work bike for my paper route. (Although back then I didn't have a patch kit and pump to change on the road, I'd have to walk the rest of the route and fix it at home)
Ask me how I figured out, it's actually NOT ok to have a little bit of tube bulging out of a small hole on the side of your tire, and rubbing against the frame...