Do you remember learning hand signals in Driver's Ed?
Just in case you happened to be driving in a car made prior to 1940 that didn't have turn signal lights. Well, those are the same signals that I use as a bicyclist. Until today.
Because no one understands them.
"Woah, that dude on a bike is making a chicken wing gesture. What is that?"
"Hey, I think that dude's a nazi! Oh wait, he's just turning right."
Language doesn't work unless it's universal. So now, I make wide gestures with my hands signaling what I'm about to do and everyone understands. That's how language evolves, my friends. And I was a part of it this time.