The hard part about teaching is recognizing when you've introduced a large leap for a good percentage of the class.

There's a famous math story that goes:

"A professor was at the chalkboard writing up a proof for his class. At one point he comes to a portion of the proof and says, 'And it's obvious this must be X'. At which point he pauses, the class waiting. Stares at the board for a minute. Then leaves the class without saying a word. He returns fifteen minutes later, continuing, 'Yes, it's obvious this must be X'."

Everything that we know can be broken down into "basic" atoms which cannot be broken down further, but are so tiny the can be learned quickly, or things built up bit by bit, which can be explained given enough time. Even things like "capital cities and states" can be taught by asking how things get named and who names them and who would name something the way they did, giving a bit of historical background etc.