There is no controlling legal authority to say otherwise. Did some King, President or Pope say it had to be the way you are saying it has to be? There’s no law or rule or regulation saying how it has to be.
It’s simply social convention and most people don’t see it your way. How you say it is supposed to be is just your opinion, nothing more.
Did you ever learn to count?
I mean it. If you think the Nineteenth Century ended at the end of 1899, then you literally don’t know how to count.