In locker rooms I consider myself average, but c'mon, "flaccid" means so many things, and not just in extreme conditions (e.g., cold water immersion). At times just lying around I am impossibly retracted, like 2". Yet at others I can still be truly soft yet almost annoyingly large, to the point at which jogging around is flop-flop city.
In my earlier sexual experiences, with little in the way of cocks (both flaccid and erect) to compare myself to, I'd always chalk up the girls' size-based exclamations to the suspicion that pretty much all women told their mates they were big because they figured we needed to hear it.
In college, I saw a lot of cocks in communal showers, and didn't reckon I stood out all that much, reinforcing my sexual-experience-acquired belief. Even when I got a rep among my friends as being hung based on their locker-room peeks, I mostly shrugged it off, but thought "maybe there's something to it, but nothing major." Besides, one of my friends was an obvious outlier who must have hung 6 1/2" every time I saw him, and his girlfriends often complained (in a sense) that they couldn't take him easily.
Then along comes the Internet and I am exposed (ha ha) to extremes - the big'uns are the ones you see on the standard sites, yet nude photos of everyday folk started me thinking there were a lot of small-dicked guys caught on camera, both flaccid and erect. Still, had a seen a guy like the original poster hanging six inches in the shower, I would have assumed he had a much larger erection than mine.
I just now checked flaccid length in what I would call a very ordinary state. 5 1/4". It's possible I was underestimating myself in those locker rooms over the years, because that can't be average. And come to think of it more than a few of those "flaccid" cocks attached to others might have been near-semis -- the shower just brings that out in some. I've also ascertained since then that I'm right at or just over 8" fully hard and a taste over 6" around, so the ladies haven't been lying. And since my early, virgin-encrusted years I've been with a lot of women who have seen more than a few dicks; several have commented noncommitally that I've dwarfed the other guys they've been with.
So I guess I'm a grower with an asterisk.