The theory that states that, no matter *how* sure you are that the
catsup bottle is empty, that the catsup is not going to come out so you can put it on your
burger or
fries, the *instant* you hold the
bottle up to look into it, the
catsup will all squirt out into your
eye.
hmm, maybe that should be the Heinz *certainty* principle... oh well...