Reading Penthouse Forum (anyone old enough to remember that?) where every guy was 8 inches or more, I thought I was average. Watching porn, I did notice that I was bigger than some of the guys, but not bigger than John Holmes, Ron Jeremy, or Peter North, the stars of that era.
The first time a woman handled my erection (18+) she commented on how big I was. I asked her "really" and she said "Yes, you're huge!". Every woman who has ever gotten me erect has commented essentially the same thing.
When penis size surveys were finally published to the web, I got statistical confirmation that & inches by 6 inches is indeed big, huge when it come to girth.