What’s it mean when someone has an ancient looking “student driver” sticker on their car?

At first, growing up in Washington State, I always assumed it was drivers ed cars or something but that doesn’t seem to be the case. Paying closer attention and after years of quietly trying to figure this out and stereotyping I propose that there are three types of people that do this, and all of them are very Washingtonian 😂

1. People with kids that long since flew the coop and they don’t give a damn. Or they have a crapload of kids.
2. People that didn’t grow up driving, or at least not in America on freeways and are terrified every time they go to work. Literally are permanently student drivers.
3. People that think it affords them some sort of privileged driving status. <~~~just a theory, is this a thing??