I guess the first problem is to wean people coming from “strongly-typed” languages, to not obsess about Float64 and such in Julia. That would cut down on questions like “why doesn’t auto-diff work on my function?”
Then there’s structured data, where multiple dispatch comes in. That’s the next thing to learn, and even then it’s not about Float64. It’s confusing because ::MyStruct and ::Float64 look similar, but a struct is more useful to dispatch on, and leaving an argument untyped can improve composability.
Maybe it should be a two-step process, to first wean off of Float64, then learn about dispatch and composability.
[edit: typo “guess”]