It's all up to you.

Some people believe in Universal definitions, some people don't. The point is that it's not anyone's responsibility to prove themself to anyone else...

It might be true that just because you say that you are something, doesn't mean that you are, but the reverse is also true. Just because you think that I'm not something, doesn't mean that I'm not. By questioning someone when they state what they believe themselves to be, all we do is insult the person. We can give them our own definition of what we believe them to be, but is it really anyone's right to declare another wrong and expect them to agree with us? Isn't it everyone's own place to state what they themselves are?