Yup yup yup. I've been coming to this realization about myself so much recently too. It's how I taught myself web/app dev with hackathons, facing a huge project head-on and "backtracking" to learn stuff as needed. It's how I taught myself machine learning by jumping into a research project with a prof without ever having written PyTorch. And it's how I'm now teaching myself higher math, having just jumped into the homotopy type theory textbook and an idea I have for application in NLP, and going backwards to learn the required category theory and algebraic topology.

I wonder whether the fundamental structure of curricula could be changed to take advantage of this fact, because I think it's true for a lot of people.

Agreed. I've found the insistence my college professors had on writing everything yourself and not using libraries or modules for common tasks to be in the end counter productive. Namely for the reason you described. To reference Carl Sagan, I didn't have the stamina in the beginning to build the universe before I made my apple pie.

Additionally, code is more collaborative than that, and it shows in a lot of engineering departments when people aren't trained on how to look at the shelf for existing parts before building something new.