Note: It IS possible, once in a relationship, to be Re-Friend-zoned. This happens when your partner, despite all other indications they made, never actually stopped seeing you as a friend. People who do this, whether or not their intentions were good, will never have a successful relationship until they learn more about themselves (i.e. how to know when they're ready for and want a relationship) and how to respect others by not leading them on.
Marcus: Nah, she friendzoned me, I want someone better than that.
Thomas: So, do you want to go out sometime?
Shelby: Sure, I'd love to!
3 moths later....
Shelby: I'm sorry, but I don't think this relationship is working...
Thomas: Why not?! Everything was going so well!
Shelby: I know, and you're great, but I just never saw you as more then my best friend.
Thomas: .........wow. I hope you grow up, because God help the next person you call your boyfriend.
Oftentimes, when the guy realizes that he's not going to "score" (how long that takes can vary), he suddenly drops his feigned friendship and moves on to other targets. The girl is left wondering what she did wrong to make such a good friendship fall apart, but of course what really happened was was that the girl had made the mistake of seeing the guy as a real person worthy of her friendship while the guy had only ever seen her as an object.
The guy justifies his behavior by getting together with his buddies and whining about being put in the "friend zone" so that he gets to feel like he's the victim.
Emotionally the equivalent of being kicked in the testicles...everyday (because you see the person who's the reason why you're in the friend zone everyday, don't you?).
As of now, modern science has been unable to find a cure.
Zone, like that idiot over there."
In this unfortunate situation, the guy is mistaken on both counts: 1) he is in the Friend Zone, BAD, cuz he doesn't even know what the hell's going on, and 2) the other guy he is refering to is a bad example, because he is obviously gay, and therefore has no sexual feelings for the women he is around, and is more acurately placed in the lesser known or traversed, "GirlFriend Zone". Currently, no known straight male has yet been this far gone, so very little is available about this terrifying area.