I'm not going to pretend I'm an expert at racing, but most of us will never fully hit our potential, there are so many factors involved age should be the last thing you worry about. Cycling is an unnatural sport, so you have to build up to it, typically someone can't just pick up a bike and dominate next week. It takes years to really get the legs to peak. I'm not saying there aren't genetics involved, but I think hard work is more rewarded in this sport than others.