I received my quarterly bill from the trashman. It's a postcard, perforated down the middle to send back half with payment and keep half as a receipt. This means I have to address an envelope, so being smarter than the average bear I figure I'll print a handful of envelopes to save myself from that tedious chore. The program I use to print envelopes doesn't list those 6½ x 3½ envelopes so it takes a little dicking around to get it right, then print a dozen envelopes, which should last me the rest of my life.
Reasonably pleased with myself, I write a check, stuff the envelope, smack a stamp on it, piece of cake. Having accomplished this I go to put the receipt and printed envelopes in my trashman folder. Golly goshes, Batman, what's this? Eleven preprinted envelopes which leads me to believe I did this three months ago.
When I got a heating oil bill a few days later, I checked for preprinted envelopes in the heating folder first, because I'm smarter than the average old man.