It must be something I ate.

Hoddeok from street vendor in Hagik-dong

Hoddeok is a Korean treat. It's fried dough filled with sugar, cinnamon, nuts, and awesome. The dough is sort of like a pancake, but a little flakier. Either way, they're dirt cheap so there's no reason not to buy them. For about one U.S. dollar, I can get three at the little stand down the street from my place. I've also seen mixes that you can buy at the grocery store if you wanted to try making your own.