Oh okay, I was just wondering on that one.
Anyways, placebo.. Here's an example of it, when they are testing a pill's effects they give some people the actual pill and some people a fake, or sugar, pill. If the people with the fake pill say they had an effect from it, it wasn't real and it was only in their head. That's what a placebo is. :]
It's basically when you trick your mind into thinking something happened. I'm not the best at explaining it, lol.