Exactly. I too have experienced the same with more smaller framed white guys having huge penises. I remember thinking to myself regularly how weird an ex boyfriend would look when naked because he penis was so out of proportion! I even once told him so and couldn't stop giggling. Of course, he wasn't exactly offended.
I will admit to something in here - I have actually turned down a guy because i felt his penis was too big for me. True story.... Believe it or not, it doesn't do it for all females. I apparently according to doctors have a small vaginal passage (and will have trouble squeezing out babies apparently, but lets not think about that right now

) so my fiance's delicious medium to large size is PLENTY for me. We're not all the same and not built the same, so thinking there is a certain expectation is really unnecessarily causing yourself grief. I remember when i was younger, i thought all guys preferred blonds with tiny asses and huge tits... boy was i wrong! I just unfortunately dated a couple guys who tried to make me think that. Misconceptions happen with everything.