Hmmm... it's not surprising that we all think we're small. This is a penis enlargement forum, after all! I know I'm a good size at 6.5 NBP / 7.25 BP, but it almost always looks small to me. Sometimes I've looked at it and thought Dang! Looks big! but usually not. Usually I see it and think, Ugh! You're pathetic. It's very strange, too, because I've never had anyone complain about my size or make any comments that might have seriously made me feel inadequate subconsciously, so I don't know why that is. My belief is that we all suffer from some form of body dysmorphia, kind of like anorexic girls, but instead of seeing ourself as too fat, we see our penis as too small, when in reality we are all pretty much normal, and in some cases extra large.
One thing you can do to help with this self-image problem is take a cylindrical object that is the exact same size as your penis. Hold it in your hands, study it, play with it, try to put it in your mouth. While you are doing this, try to put yourself in the place of your sexual partner mentally, handling your tool, and how she would see its size and experience it. I know this sounds gay, but try it. I think you will come away with a better perception of your size if you do this. I tried this myself and after trying to get my mouth around a 6" girth, I realized my wife has the ability to unhinge her jaws!

I do not know how she gets it in there, especially without biting! Although I do not see my penis as being any larger, I came away from the experiment knowing, Damn! That fucker is pretty big!