So the deep Freudian fear in men is the previously mentioned vagi-with-a-bite. The deep Freudian certainty in women is men really do think with their wangs.
Well, ladies, thanks to Liz Ditz (who receives a brainy no-prize that will do something embarassing if she rubs too hard when she dusts it), we have the ultimate truth, from that paragon of journalistic integrity, Weekly World News:
LADIES, you may believe that every man thinks with his penis, but Lionel Tampling is in a class by himself. Astounded doctors have found a rudimentary brain in the Australian's trouser trout!