Gotta love life in the Czech Republic...

If someone sneezes, the polite thing to say is (translated into English), "Say hello to Mr. God" or "Say hello to the Lord God" ("pan" can mean either lord or mister -- and I think that's where Peter Pan comes from). Apparently, it was a common belief way back when sneezing somehow thrust your soul into a spiritual realm. Perhaps it had to do with sneezing being a sign of sickness, and sickness way back then wasn't so very far from death (so you'd better say hello to Mr. God, and mind your manners, too). A similar belief also gave rise to the more familiar "God bless you." The proper response to "Say hello to Mr. God" was, "May God give it," the "it" presumably being health, so you wouldn't croak. That's the polite way to handle a sneeze.

The slang way to handle a sneeze is very different (and, unfortunately, that's the way a student of mine taught me when I first visited the Czech Republic, just to get me into trouble). When someone sneezes, you say, "Drop dead, you monster!" That sounds very strange, but the monster that you're addressing isn't the sneezer, but the disease the was presenting itself in the sneeze (and, during the Plague, might well have killed you both!). It's such a colorful language.