I think most people add like 2'' to their cock measurement in their mind, somehow thinking conditions weren't optimal at the time of measurement or whatever. Isn't it true that statistically 50% will have lower than average size? I don't understand statistics. But on comment threads everyone, even the ones sort crying that they don't have a monster dong, are at least "slightly above average" so it's ok.
I have a friend who got into porn like 15 years ago, and when rumors started we googled him of course and it looked like a 10'', I didn't measure but it was "porn star large". Another friend saw the same pics and said, "I didn't know you could shoot porn with a baby dick." Delusions.