I was in the habit of giving the ketchup a good vigorous shaking before opening it. That way it would pour a lot easier. Once I tried that in a restaurant and the previous patron had not screwed the cap on. Ketchup went up the wall and both my date and the waitress got a good laugh on me. Another time we got pizza for lunch at the print shop. I grabbed two slices and flopped down in one of the office swivel chairs only to have it flip on its back. I ended up with the pizza, gooey side down, on my face. Fortunately the pizza was not too hot.