I have known about gender for over 50 years. It was that pesky continental habit of assigning sex to words. In German, for instance, a dinner fork is feminine (die Gabel), spoons are masculine (der Loeffel) and knives are neuter (das Messer). So Germans have pretty sexy dinner tables.
In English, of course, we have no such nonsense. We do other crazy things, like spelling our words according to how they were pronounced 600 years ago (all the "silent" letters in "knight" were once pronounced, for instance)
So for centuries "gender" was a property of words, foreign words in our case. Around two decades go, however, the Left, with their usual abuse of words, decided to use "gender" as a description of people. Your preferred use for your penis was described as your gender. If you made normal use of that organ you were "cis", for some obscure reason.
But the sex drive is a strong one, as Freud emphasized, so the sex urge did occasionally get derailed in various ways for various reasons. And your preferred derailment became your gender, according to the Left. So the BBC recently announced that there are 100 genders.
Being myself very "cis", such extensive creativity rather surprises me but I can see no obvious harm in it. Why the rest of us need to be bothered by it, however, I have no idea. All I can make out of it is that the derailed folk want to be praised for their derailment. Good luck with that!
So let the Left prattle on about gender. I suppose it draws our attention to the fact that there are a variety of sexual practices -- but we have always known that.