Questions about the "Rules of Sixes"

English is not my native.

So I've been listening a lot of Kevin Samuel's work and he is emphasizing a lot about the rules of sixes, and as I recently started to fit in the 6 figure salary, I was thinking I should search a little more about this thing, although Kevin only mentioning three of the rules and not four, so the 6 inch dick is an addendum as the Urban Dictionary states:

1.) 6 feet tall
2.) 6 figure salary
3.) 6 inch D
4.) 6 pack abs

So serious question, 6 inch D is considered bigger than average or why is it on the list? I didn't measure my pee pee since high school but hey, today may be the day. I'm curious.

Level of Retardation of this post: 6/10 [Not high enough for deleting by mods (please?)]