I like to say programming is about knowing which rabbit holes to plunge down and which to step over. There's too much to know to go depth-first down every rabbit hole. Go breadth first and accept gaps in your knowledge - everyone has them. If something never comes up and never causes an issue you need to look into, and the project gets done, it doesn't matter. There's always an improvement that could have been made, but done is better than perfect because perfect never gets done. But the projects never getting done or even started - speaking for myself, that is corrosive to my motivation.
I've written a lot of Rust. I've read less than half of the Rust book. Your competence in Rust is a function of how many lines of Rust you've written; getting to the point you can start working with it is more important than completing the book. Jon Gjengset's videos were really critical for me there, seeing how he worked in Rust made it possible for me to develop a workflow. (I broke down what I learned in more detail at one point [1].)
Rust is an example I've honed in on because you mentioned it and I related to it, but this is broadly applicable. Dare I say, more broadly than just programming, even.
(Also, note that I'm a giant hypocrite who shaves yaks and struggles with perfectionism constantly. I learned Rust 5 years ago to start a project, and I've written 0 lines of code for it. If I sound critical, that's my self criticism leaking through.)
[1] https://news.ycombinator.com/item?id=38020654