1565 Per Dollar

So I have questions sometimes. The other day I was typing a report and I decided to use the percent sign. You know the one. A forward slash mark with a little circle on either side of it. %. If you stare at it long enough it looks like some cartoonish or Picasso-like rendering of the eyes and nose of a face.
Add a parentheses mark and it gets even more Picasso-ier.

%)

By the way is it "a parentheses" or "a parenthesis."
Why isn't one of them just a parenthe?
I digress. But then again, I digress when I say "I digress." Is that a trigress?
Where was I? Oh yeah. What brought me up short was when I wrote out the sentence, "There'll be 50% less of the $100 than people had thought."
Why is the percent sign after the numbers when the dollar sign is before the numbers? On the face of it, the percent sign is where it should be. You say 12 percent, so the percent sign should be after the 12.
When you say 100 dollars, the word dollars is after 100. But when we use the dollar sign it's before the dollars. And we don't say "dollars 100."
If we use the number sign, that crosshatchey deal, we put it before the actual number and we say it like it's before the actual number. #2 is written with the number sign right there, in front of the 2. And it's not just money stuff. When we use the cents sign it makes perfect sense too. It's after the number.
6¢ — It's very sensible.
I'd bet dollars one hundred know one knows why.
America, ya gotta love it.