Break a Leg in the Theater

It is customary to buy packets of crisps to be shared while having a drink in the pub. The crisp packet is often ripped open in a certain way to allow everyone to take crisps from the bag. That's known as corpseing, isn't it? Corpseing where you can't stop laughing,. I think that's a theater thing. Why do they always call things such weird things in the theater? Because it's the opposite of corpseing would be you're dead and you can't move. It's like in the theater when they say break a leg, which means good luck. Well, you know why that is, don't you? No, I've told this on