I've never been told my dick is small by a woman who hadn't already told me it was big. This leads me to have two competing hypotheses about the size of my penis. It either:

1. undergoes a cycle of drastic size changes that follows a sawtooth function, gradually decreasing throughout a relationship to a minimum during the relationship-ending argument only to instantly shoot back up to a maximum upon getting with the next chick, or it:

2. Remains a consistent normal size while a series of women repeatedly told the same set of contradictory lies as a method of manipulating my feelings one way and then another.

Now to design an experimental apparatus to test these hypotheses.