There's no one way to promote a movie on a late-night talk show. Some like to just chitchat until they can intro a clip, others want to talk about poop. By others, we mean Jennifer Lawrence, who used her spot on Letterman to discuss how she hasn't been feeling too great recently. She thought it was an ulcer, but it seems to have more to do with stress and weird, hippie Woody Harrelson drinks. She later talks about how she'd rather hug than shake hands, which is a good thing to know if you ever meet her. Just don't squeeze too hard.