I just wanted to add in here that, although I'm sure we've all thought this way at one point or another, even if you do have an intersex condition that doesn't have anything to do with being trans*.
For example, two people with identical intersex genitalia could have different gender identities and they would both be completely legitimate. I know it seems obvious since we're on a trans* forum, but it's easy to forget, that two people with ANY time of genitalia (whether it be male assigned, female assigned, or intersex) can have much different gender identities.
So as much as it is tempting to wish you had an intersex condition for a "good reason" for being trans... it isn't.