The first thing you must understand is that gender is a social construct. “Woman” and “man” are concepts arbitrarily invented by society. They have nothing to do with reality. A child is assigned one of these labels randomly at birth by primitive, backward-thinking doctors who, for no good or objective reason, have decided that a human child with a penis must be a boy and a human child with a vagina must be a girl. These words are all interchangeable, as are the body parts. None of it means anything, really.