Good question, it really got me thinking. And I was trying to come up with something not related to being trans.. but..
Quite frankly: hormone replacement therapy. I've been on and off a few times, and the results were clear and reliable.
Now, as my brothers, sisters, and brothersisters know, it doesn't magically solve all your problems. But it comes pretty damn close!
Let me try to explain the feeling. You know when you're down and you try to rely on a good friend, but suddenly they're not there? You shift your balance to lean on them, but suddenly there's just air and you fall over?
It was like that for me nearly every single day before hrt, but instead of with a friend, it was with myself. I am talking psychologically something was just missing. And trust me when I say I have tried a ton of medicine over the years, and none of it worked or just made things even worse.
And now, it's totally different. It's like having this psychological membrane that always pushes back up, no matter what shit I am trying to pull. Imagine being on a trampoline. You can make mistakes and the membrane will simply bounce back and push you back up. In other words I can eat crap, sleep badly, isolate myself, ignore my responsibilities, fall into a depressive hole for a day, and yet something in me just automatically pushes me back up. It's solid and reliable. I haven't had a single day without it and it isn't variable. It keeps surprising me over and over.
The funny part is that I am quite transphobic and self aware of that. I suppose we are all taught this attitude growing up in western culture. So whenever someone insults me, I totally get it, albeit that I find it rather unrefined behavior of them. I'm from a rural area in the bible belt, so I'm quite familiar with the white trash mindset. If they just wouldn't bike away all the time I'd be able to strike up a good talk with them. Simple truth is that I can't alter the facts and I have a male shaped skeleton.
Honestly, I think a lot of women worldwide would be glad to make some sacrifices to be able to live in my body. Sure, it has some downsides, for example I'll live shorter. But it provides me with safety, which is a major concern for women. I can walk around at night in the park just fine.
Well, that's just my personal experience. It's different for everyone.