My theory is, that is was invented to protect sensitive parts from rubbing against the zipper. What do you think?
So that women could look sexy IMO. Also, as far as bras are concerned, so our don't end up around our ankles.
It's probably to protect your pants from smelling like pee. Little droplets of pee come out sometimes, staining your pants. Enough of that happens, and you would get pee-smelling pants. I for one am glad underwear was invented. I wash my pants once every few weeks. If not for underwear, I'd be washing my pants every other day.
Probably hearkens back to the old days in a twofold sort of way: Early man would add layers to keep out the cold, like a buffalo skin over a loincloth, and it probably sort of evolved naturally from there. Then there was the 1500's on, when the clothes were heavy and rough, and silky undergarments probably help preserve the outer layers from stinking and also prevent chafing. Especially since those nasty fuckers only bathed once every spring.
underwear existed LONG before zippers existed. one need only remember that years ago, much clothing was made of wool....hand woven wool. Any questions?
I heard some Asian woman centuries ago made something like a bra when she discovered that using silk to hold up her boobs made them look better. Dunno how true that is. Dunno about other types of undergarments. I'd like to just say, "BECAUSE IT'S SEXY!" but that didn't come to mind at first.
You don't have to tell me! My uniform is a mid-to-late war style. It's a wool-cotten blend that was invented in 1862. It's not as irritating as 100% wool, but it's still a little scratchy. Not as hot, either. They didn't wear those long, cotton drawers for nothing. Helps keep the wool away from your skin. I have several pairs.
