I think the directions on a frozen pizza have stopped saying Pre-heat the oven.

 when I was a kid, did that with pizza in it, and thought it was done after 5 minutes, almost burnt.

vomited all over the bathroom toilet.  called my parents, they were up at Weeks Tap, they came home, and had to clean all that up.  ahh, I never did that again, pre-heat button on the oven.