I have. I'm a darn good liar, too.
I've long told everyone that I'm allergic to peanuts. I try to clarify that I won't die, so that they don't go to extreme measures to avoid them around me, but I try to make it like there's potential for big drama. Why would I lie about such a thing? I hate peanuts that much. I hate peanuts more than Charlie Sheen hates Baby Jesus (hoping to monopolize Google searches with those keywords). I hate the smell of them, I hate the taste of them, and I absolutely hate peanut breath.
I had convinced everyone around me: family, friends, coworkers, girlfriend's family, etc. of this allergy. Suddenly, 3 years ago, as a result of one of those chain Facebook notes where you say things about yourself that others don't know, the secret was slipped. An ex-girlfriend, one who Annie already dislikes from her name alone, made a point to emphasize that she already knew it. This sent Annie over the edge. Apparently her family had been going out of her way to avoid peanuts at family functions while not notifying me so that I didn't feel awkward. (I doubt that they actually did this, but I'll give her the benefit of the doubt.)
Anyway, if you don't lie, people will say things like "but it's so good you have to try it" or "you can't even taste the peanut butter" which is always, always a lie. So, lies were required to keep my life sane, and the lies came so frequently that they appeared to be true. Now, I wonder if I would actually have a reaction to peanuts if exposed, as a self-fulfilling prophecy curse for being a jerk.