I contemplate transitioning all the time. A huge part of me wants to, but another part of me feels it would be better to hold back and remain a man, just one who dresses up as a woman often.
I'd love to live full-time as a woman. I'd love to be one of the girls, to be able to go anywhere as a female and not be hiding anything (or just go somewhere as a female for that matter - I've never left the house dressed even), and most importantly, to have the body of a female.
That said, I have a billion obstacles in my way. I have a girlfriend, career aspirations, a complete lack of any money whatsoever, a family who wouldn't accept me as a female (much less as a CDer), etc. It's just not feasible at this point in time, nor will it be feasible for many years to come.
If I had zero constraints on me, I seriously might transition, and I would want to start it soon, because I would love to be a woman while still in my 20s (I'm 19 right now). But that certainly won't happen.
It's something I think about all the time, and generally something that I seriously contemplate every single time I dress. But I know it's not happening, whether I want it to or not.