While we are on the subject of myths handed down from generation to generation (and while I wait for a useless courier to deliver a parcel) were you - as I was - told by some teacher at school that every glass of water drunk in the world contains a small percentage of Julius Caesar's urine?
A mature friend of mine who likes hamburgers told me - with a look of panic in his eyes - that he had read that every hamburger that is eaten takes 10 years to digest, and most people are walking around with great lumps of hamburger rotting away in a dark corner of their gut.
How on earth did that one come into being, and - even more inexplicably - how did it attain any credence whatsoever?
Well, here's one theory: It is a fact (so I am told) that your body completely changes its cell tissue over a cycle of about 7 years. You sort of turn inside out over that period, and either the cells fall off as dead skin, or you burn them as energy or excrete them along with the hamburgers. This is one theory which could explain the 'seven year itch', but even that notion - that you wake up one day to find you are married to a different person - is just a feeble excuse for adultery.
Now take a mischeivous or unscrupulous person who happens not to like hamburgers, not to like MacDonalds or not to like the way that cereal crops are being grown to feed cattle for the hamburger market and not starving humans, then give them the seven year turn-around biological explanation, and it is just a short step to create a myth about hamburgers being completely indigestible. Put it in print and it will become verifiable, and these days getting stuff into print is as easy as writing this blog.
People will naturally believe things which they either want to believe, or do not want to believe, and they don't have to involve statistics (73% of which are made up on the spot) at all.
What is the most ridiculous thing which you have found yourself believing in, if only briefly?