[QuickSilver]

For some reason, this happens to me all the time in the grocery store. Someone will be lingering in front of me, I'll open my mouth to say "excuse me", and out comes a brisk, cheerful, "Let's Go"!

I've also found that when I'm thanking the cashier, I often say, "Good Boy!" Talk about embarrassing. I think it sounds so weird that people don't understand what I said. At least, no one has looked offended, yet.