Here is the "Why now?" for me:
I've known for my entire life that I wanted to be a girl rather than a boy. As a child I did girly things, dressed up in my (only slightly older) sister's clothes - she even was all for dressing me up at the time, although neither of us understood, got, or cared about the implications. However, my parents, other adults in my life, and even other kids basically shoehorned me into acting like a male and repressing my desire to be female.
Farther down the line, about 12 or 13 when I started to get the first signs of puberty, it reemerged. At ages 14-18 it intensified. At 19 I was going to transition - but I was too much of a chickens**t to go through with the whole interacting-with-other-humans aspect of transitioning and starting HRT. I wish I had started back then. At the same time though I'm glad I'm starting it now, because right now I have an -amazingly- supportive girlfriend.
For me, why I'm about to start HRT (got the all clear from therapist, just waiting for my endo appointment to arrive on Friday

), right now, having -just- turned 25, is for multiple reasons.
For one, I've noticed since I backed off from transitioning at 19 - pretty much every time I see a female, especially ones with very feminine features and good looks, I feel -raging- jealousy. It sucks, because I don't want to feel such negative emotions towards other people, especially over something they just were born as and had no control over. It's just a -daily- reminder (more like many-times-a-day-reminder) that I'm in the wrong body.
On top of that - I had a near death experience last April. My heart literally stopped beating twice and they had to shock me back to life.
This experience changed my life in so many ways. It even changed the way I perceive reality. Countless realizations happened, countless things were thought in my mind. I could write a million words and not convey what happened. Not to anyone. I feel like death is the most important moment in your life. I won't even go into how the experience went from my perspective, seeing as you'll probably all think I'm a nutter or something.
But one of the biggest things you realize when you are dying/dead (don't know how to classify it) - is this: Your biggest regrets in life. First thought in my head was "wow, I went out on this trip, and my girlfriend is literally driving to meet us here, and when she gets here she will find out I died." Nothing worse ever felt in my life.
The next thoughts were on all of my regrets in life. Want to guess what number one was?
It was the fact that I didn't transition. The fact that I didn't tackle the biggest problem in my life, yet I didn't even recognize it as the biggest problem in my life - that thing which my life must be revolved around solving before anything else. But dying/thinking I was dying/having my heart stop and me know it was about to - it clarified everything I -needed- to do in life.
All the wrongs I ever did anyone ever in my life PALED in comparison to the wrongs I did to myself. Even just that -one- wrong.
Now I don't care about any obstacles, for anything in life. Life is almost like how I once viewed my characters in video games. I'd do all sorts of stuff, basically whatever I wanted. If I messed up? Oh well, I'll fix it, I'm having fun and doing what I want. Now I apply the same thing to real life, because it's essentially the same thing as a video game. I'm not going to risk dying over something stupid, but of course, I'm also not going to risk living without actually living - doing exactly what I need to do in life to feel satisfaction when I really die.
This post has me literally in tears - there is so much I wish I could tell you, or anyone, but I know I -never- will be able to actually convey these things to anyone with words, and even if I could they wouldn't believe. I never talk about my near death experience to people, in fact this post is the most I've ever typed about it. It just frustrates me to have the most important moment in my life be the one thing I have no option but to keep to myself.