Well, I guess I live in one those little bubbles. My bubble has measuring tapes and facts.
In 1940, Robert L Dickenson mentioned that in the early 1900's (not sure why the 40 +/- yr gap??) he documented the longest penis at 13.5 inches. To my knowledge, this still stands as the longest "documented" penis.
Speaking of lpsg, we have over 400,000 members from all over the world, probably including most, if not all of those countries mentioned. Our longest members are 9-10" (albiet, some questionably)
**up pops the member with the "photo" of his/her 12"er**
I am average height at 5'9", and from the base of my cock to the very top of my knee cap is 14.5". As mentioned above, 6' tall and it's going to be around 16".
Even
quercusone, as awesome as he is, with an obviously very large and long cock, is several inces shy of his knees.
http://www.lpsg.org/gallery/showphoto.php/photo/253801/cat/500/ppuser/35301
So, in my little bubble, the answer is still "NO", no normally proportioned man is going to have a cock down to his knees.