I know that I couldn't have transitioned because I just wasn't ready. I first had to experience a long, long arc of desperation and spend a couple of decades spiraling in on myself until transition was simply unavoidable. In addition, I would likely have been rejected by the establishment and not even been allowed to transition. My biggest obstacle, of course, would have been my gayness: For a long time, there was "no such thing" as a gay trans man. I could have covered up my one episode of child molestation, and I could honestly tell a skeptical therapist that I wanted a penis (I just didn't want the bottom surgeries that were available at the time). But there was no way to cover up my long-term relationships with men or my extreme preference for men or my own perception of myself as a gay man.
All the same, I did have certain periods during which, if I'd had the knowledge and the appropriate funds, transition would have been easier to accomplish--times when I was between jobs or between phases in my life. But, looking back, I just don't see transition as a viable possibility in, say, high school (no way!) or 1983-84 or even 1989-90.
I turned 28 in 1990. By then, I had gone through most of my big adventures except for finishing my undergrad education and going to grad school. I had left my parents' house and essentially cut them off. I had run out of money and been pretty desperate. I had had health problems and was just starting to get them under reasonable control. I had been in several relationships with men, had a number of one-offs with women, lived in a triad relationship for quite some time, and done the local swing party circuit; I was pretty popular at those parties even though I never saw myself as attractive. I had a nice body and a great rack. Someone, and often a handful of men, always wanted to sleep with me, and I could have had a lot more sex if I'd been so inclined.
The thing is, some of that time was...not a waste but not particularly productive, either. I couldn't transition because I lacked the self-confidence and conviction (and I didn't know I could transition until 1988-89). But I was unhappy in certain profound ways. It was kind of a chicken-and-egg situation; as a girl, I would never have the kind of confidence I needed to transition, but I couldn't attain that kind of assertiveness until I lived as a man. In a lot of ways, my sexual exploits were just my frantic way of trying to find myself. I didn't really enjoy sex with strangers although I'm glad I experimented. The three-way was doomed from the start although I didn't know it.
BUT my last relationship, which existed only after I initially came out to myself, I honestly would not trade even though I was often so messed up while I was with my ex. I sometimes wish I had transitioned in 1997-98 (I had a great opportunity and ample funds). But my relationship was amazing. I didn't think I could be happily monogamous, and that relationship taught me that I could. I didn't realize I could love someone so fiercely and for so long, but I did. Perhaps because he knew what I was and accepted it to an extent, I was often able to be happy. Not all the way through; my "happiness" was more like a chocolate coating that wore thin at times and revealed an unhappy core. Yet it was there. If I had transitioned too early, I would have missed out on that.