Why'd I change genders?
Obviously it's 'cause I was so God-damned manly. I was such a dead butch manly man that all the other guys were reduced to cowering pantywaists in my presence. A real man can't stand that kind of sycophancy. It's not enough to be a man amongst men, alpha of the alpha males. A real man needs challenge and struggle! Transitioning into a woman was the only thing left to give all the other guys a fighting chance at competing against my studly mojo.
Besides, after a while you just get sick of all these sexy lingerie models licking beer off your muscles. You start shouting, "Get off me bitch! I'm trying to chop firewood for the cabin where I wrestle my bears!" But it's too late. The pheromone addiction's already got them.