Back in 1823, Charles Macintosh sold the first raincoat.
So my first question is, “Why did it take so many millennia for someone to realize raingear was a good idea?”
I mean, really, 1823!
Well, the reason was, there was no waterproof material until 1823.
Born in 1766, Macintosh devoted all his spare time to science.
Yes, he was a nerd.
A chemistry nerd to be exact.
Before he turned 20, he quit his job and started making chemicals where he invented new processes and products.
One by-product of his efforts was naphtha which allowed for the creation of waterproof fabrics by cementing two thicknesses of cloth with natural rubber. The rubber was made soluble by the naphtha, and voila! you have raingear.
He was elected a fellow of the Royal Society and died a very rich man.
Now you know.