Cloud Nine

I was just watching a Dairy Queen commercial, and something hit me. I think I know where the expression "on cloud nine" comes from. It was the new commercial about the midnight truffle blizzard and how it'll put you on cloud nine and make you lose your breath... Well, maybe if something is so good it'll make you be on cloud nine and lose your breath, there's a connection, right? So I thought, what else makes you lose your breath? And it hit me. Duhh, if you travel too high in the sky you can't breathe. So if something makes you lose your breath, that's why it puts you on cloud nine. xD