> What's the "?" doing? Why doesn't it compile without it?

I don't understand this line of thought at all. "You have to learn the language's syntax to understand it!"...and so what? All programming language syntax needs to be learned to be understood. I for one was certainly not born with C-style syntax rattling around in my brain.

To me, a lot of the discussion about learning/using Rust has always sounded like the consternation of some monolingual English speakers when trying to learn other languages, right down to the "what is this hideous sorcery mark that I have to use to express myself correctly" complaints about things like diacritics.