"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."
-- Shakespeare, Hamlet
Saying that you're "open-minded" can be extremely disigenuous -- it's easy to say that you're cool with stuff like gay marriage, medical marijuana, or criticizing the government, while still leading a life that is pretty pedestrian, non-threatening, and maybe more than a little uptight.
Not that there's anything wrong with that.
The thing is, there's a whole world of off-the-wall living going on that goes waaaay beyond all of that. Are you really cool with people who have radically different ideas about sex, love, drugs, politics, and religion? If so, is it because you're a "deviant" yourself, or just a genuinely non-judgemental vanilla?