I was in the communal kitchen a while ago when the following scene occurred:

Me:
She: Do you know what the ingredients are for pasta sauce? I know that there's ketchup but that's it...
Me: Uh....I'm *very* sure there's no ketchup in pasta sauce...

But it was too late. Her friend had emptied out an entire bottle of ketchup (one of those large Heinz squeeze bottles) into a saucepan and was stirring it over the stove. If I'm not mistaken, there were a couple of quarters of tomato floating around too.