LOL no, I hadn't heard that one yet. I'm German and jokes about Jews are not PC over here (still that's an excellent one, heehee).
As an athlet I, too, prefer briefs. There is less chafing when running. The wider boxers may be airy but they move too much when you do and that can get very painful after a while.
At work I wear long-legged skiing underwear in winter (and 2 pairs of woolen tights over them), as my profession requires me to spend all day outdoors which at temperatures of -25°C can get a little cool around the thighs.