Imagine you’re trying to learn quantum field theory, and you just got to a tricky part: deriving the LSZ reduction formula (don’t worry, you don’t have to know what this is!). The calculation and algebra are a little messy, particularly if you’re working with the fermionic case. When going through the derivation, it’s easy to lose the forest for the trees.
When something doesn’t make sense, it’s easy to look at it and think that it is just a collection of random rules. Unfamiliar topics look incomprehensible, so naturally we miss the structure behind them. This doesn’t mean that the structure isn’t there. It’s simply that you can’t see it because you don’t understand the topic well enough.