where n why comes "ladies first" from?

Answer 1

The middle ages. A specific concept of treating women as special, sacred almost, grew up around the concept of chivalry, what knights are supposed to do. The idea was that the man is the protector, the woman the sacred vessel of life. It is probably most familiar in the stories of King Arthur and the Knights of the Round Table, but it was all over Europe and lasted for centuries. Gradually, women found the role too confining. In modern times, the feminist movement told men they did not want to be put on a pedestal, worshiped and pampered and protected, but would rather be equals in the professions and the marketplace.

Very foolish, in my opinion. They gave up privilege for everyone, even those of us who liked it. That's why when a man holds a door for me, or otherwise treats me like a lady, I say, "Thank you! There are still a few gentlemen left in the world, I see."