Im guessing the "No" makes a bell curve of those who know and those that dont

IIRC Hindus invented this number system (with glyphs for 0-9), and then the Arabs starting using it. Eventually the west started using them and credited the Arabs.

As for how they are written, everyone used the same shapes, and then they probably just ended up changing over time (“Hmm…how do I write that number again? Oh whatever I’ll just make it up”)

Feel free to do your own research though.

I'd go on a youtube journey. I'm sure you'll find some cool linguistics videos about it

1 and 9 are the only ones that seem more arabic than hindu. Hindu gets १ and ९. Everything else is pretty close to source.