Ever Meet a Real Bisexual?

Everyone always says they're bisexual, blabbing on and on about how "sexuality is fluid, and I don't really like labels"--but usually I find these are just gay men who are afraid to come out. I know there are real bisexuals out there--mainly because I've heard that there are--and I do
think it's a lovely idea to actually crave sex with people regardless of gender. I'm just wondering how real a phenomenon this is, as opposed to a smoke-and-mirrors coverup designed to keep antsy gays in the closet.

Most of the guys I know who say they're bisexual end up doing Bette Davis impersonations after a few drinks, and when you invite them to an all-girl bar, they get excited, thinking you mean Splash. But do you know anyone who REALLY is equally attracted to both men and women and effortlessly glides between those two dating pools without a second's thought or self-consciousness? If so, do you ever suspect they're full of shit?