...if you find random nicks and cuts on your fingers and can't remember how you got them
...if you'd pay more for a hand saw than a circular saw
...if instead of measuring your inseam and then buying a pair of pants, you prefer to buy them slightly larger and then shrink them in the washer a couple times until they fit just perfectly.
... if you sign documents with a knife instead of a pen because the line's too fat.
...if you know why your butts are not firmer.
...if you know that relieving gas and getting a board flat can both be called 'passing wind'.