I don't think, that in the back of any mans mind, at any age, is he really satisfied with his cock size. He may say he is but look at some of these guys with close to 8 inches they still pumping and stretching, wanting it to be longer and thicker.
I know with a cock on the lower side of average I have and will always wonder why I am not larger even if I have lived to except its size. Oh yeah you grow up seeing other guys cocks that dwarf what's between your legs and you still wonder when you look in a mirror. Size still doesn't effect the real sensations whether small or large, when you cum it feels damn good.
When you get dressed though and there is no exceptional bulge in those undies, or those jeans, or shorts you still have to wish.
Sorry may have taken you off course on your thread. My bad.