Cycling (in my opinion) is not about comparing yourself to others, but rather comparing yourself to yourself. Just like swimming, my goal is to always just do better than what I previously did, not better than others. Yes it is nice to be faster and be able to ride farther than other people, but if you aren't getting faster or riding father than you previously were than you aren't getting any better.
Seeing as you started out doing only 6-10 mile rides and now you have done a 20 mile ride, you are obviously getting better. Don't worry about how far others ride, and just get out and ride and make a goal of riding a little bit farther or faster every week and you will get better.