I'm not sure if it's a skill so much as it's a talent, but I would love to have a winning intuition with gambling. It's the most amazing mystery to all of us, but somehow my mother-in-law consistently wins at casinos no matter where she goes. It's silly how much money she makes gambling, or heck, that she makes money doing it at all. It's how we know that the returns in Vegas are generally just lower than you find elsewhere abroad (not to mention taxes).