You do need to know there is such a thing as a b-tree, and when you might want one, and that balancing is a thing that you might want to do, and when to do it - even if you never actually implement one from scratch yourself, you absolutely do need the vocabulary to refer to it and a general understanding of the concept. That's what a lot of self-taught coders are missing - the knowledge of the theory that makes it easy to communicate with others.