The development of sexual characteristics. It's a nightmare. You probably think it's worth it if your big goal is to have kids, but I don't. I don't need a bulky skeletal structure that feels like I'm trapped in armor at all times, I don't need the constant annoyance of having to masturbate all the time, I don't need the raging hormones and extreme anger, I don't need to lose my hair in exchange for a beard and hair all over my body, I don't need to look so mean nasty and threatening that even animals don't trust me, I don't need the devastating loss of intelligence particularly in the creative areas, I don't need the loss of vivid senses, and above all I don't need to lose the ability to feel emotions other than rage and self-pity. All of those things are puberty's fault. Oh, and lucky me, I also ended up with gender dysphoria on top of that, so it's even worse! Ever since all this started I've wanted to die. I was a happy child with a bright future, and a much better person. Then this happened and everything turned bleak and hopeless, and there's no sign that it will ever end.