Don't say it

Never, ever tempt the gods. When you are in good traffic, say nothing or the evil traffic gods will ruin your ride. When you are pleased with your contractor and the work he does, say nothing or he will leave you without finishing. When you are enjoying your blessedly cool house and the seeming efficiency of your new windows, say nothing or you are sure to come home to a house with lovely windows -- but an air conditioner that has chosen to go on the fritz on the hottest day of the summer.

Gah.