Yeah, unless they're one of those overly optimistic, so-happy-that-they-should-be-in-a-mental-asylum motivational people. I hate them too much to do anything they say that I didn't want to do anyway.
Haha, well, yes and no. Just the other day I was in a bad mood and my friend randomly started singing that, and when she asked me why I wasn't clapping I explained that I wash;t happy. So she changed it to "If you're UNhappy and you know it..." and I just decided to start clapping. And she got me laughing by the end, anyway!