Brit has kindly suggested that, as the iconoclast's iconoclast (making me an iconophile, and indeed I quite like a nice icon), I might one day write for the Dabbler on things that everyone knows but that aren't true. (For example, that the Chevy Nova in fact sold very well in Latin America.)
Obviously, ever since I've been wracking my brain for something sufficiently obvious to be worth disproving, and I haven't really come up with anything. The closest I've come is to knock down that terrible piece of trendy job advice: follow your passion.
Whatever you do, don't follow your passion. Following soon becomes stalking; stalking becomes sneaking into it's bedroom late at night and abducting it; and abducting it becomes burying it at the crossroads while eating its still warm heart. Following your passion will kill it.
This follows from Sturgeon's Law: 90% of everything is crap. So, if your passion is movies and you become a film critic, what you actually spend your time doing is mostly watching crappy movies. If you love cooking (which usually means you like making one big meal on the weekend after planning a menu and shopping for specific ingredients), what you actually spend your time doing as a chef is cooking crap. (If you open a restaurant, rather than just become a chef, what you actually spend your time doing is losing money.)
Telling people to follow their passion is telling people that, if passion is their passion, they should become a prostitute. Actual prostitutes are not in it for the sex.