Today is the 410th birthday of noted French philosopher and mathematician Rene "I think therefore I am" Descartes. Known as the father of both mathematics and philosophy (he also fathered a daughter, Francine, out of wedlock), Descartes' work and life are plenty fascinating. But we bring up his birthday only because it is our best opportunity in weeks to share our favorite fact in the entire history of facts, which we learned from Britannica via floss contributor A. J. Jacobs:

Rene Descartes had a fetish for cross-eyed women, a fetish that turned out to shape his beliefs about free will and presage Freudian psychology. After spending his early adulthood ceaselessly attracted to women with strombosis (as crossed eyes are now known), Descartes determined that his fetish went back to his childhood, when he'd had a cute and cross-eyed female playmate. By recognizing the root of his fascination, he was able to rid himself of it with his free will.

That's all fine and good for Descartes, but in retrospect, maybe he should have kept his fetish. When you look like a very surprised Inigo Montoya, after all, you can't really afford to be picky. Seriously: