From my experience, most people in this situation either learn the hard way and become a better sub/Dom/me as a result (whether they originally started out as such - they either become better at what they claimed to be or find they are better as the other) or they give up and decide that they prefer vanilla (usually once they realise that no, you cannot get laid any easier by claiming to be a Dom and taking advantage of all that 'sexy, easy, sub pussy' that is, by reputation, hanging around the BDSM scene). Peer pressure is a great tool when used for the purpose of good - in this case demonstrating to someone who does not know exactly what it means to be a sub/slave/Dom/me rather than a wannabe. I should know because I started out as just such a wannabe and I think many here did likewise.