Man or Boy

I had a enjoyable conversation today and it prompted me to wonder or question. What is the definition of when a boy becomes a man? Is it when the boy hits puberty when he gets hair on his chest, voice changes? Is it at a certain body height or a body weight. Or maybe the size of his cock big or small or the size of his bank account? Maybe when he gets married or has children treating them good or bad? I believe that every man, woman, boy or girl has a different idea of when a boy becomes a man and or his defining actions.