It seems there is a steep drop off in the bell-curve between 7 and 8 inch, as per my pathetically unscientific graph. It’s probably even steeper.
So if you’re e.g. 7.1 inch, you’re only an inch away from a much more extraordinary level of hugeness. (see the shaded areas in the graph). This is the inch I think our brains tend to exaggerate in our messed-up size perception, e.g. guys over 7.3 round up to 8, guys aproaching 8 seem like they must be over 8, guys who just pass the 8 inch mark might claim 9 or more, and hence the mythical 10-12 inchers we hear about, they only need to be 8.5ish for some people to believe it.
I know the graph is bad, but if one agrees that the slope is in more-or less the right place then it does the job. But what does everyone else think?