I don't usually realize how big i am,especially when it is soft. I always think i am small, but i notice from how guys look at my dick in public situations (urinals,showers,locker rooms etc) and then i think: "I should really put a pair of glasses on,cuz i'm bigger than most of the others". But for me being big would mean having a 9-10 inch cock on me. I have a different perception of my cock from the one others have on me, or from the one i have towards the others. It's weird, i know.
Anyway, i just piss. I wonder about measures only if it is very cold outside and my cock becomes small with tight balls, which i hate showing.