Even seemingly difficult concepts and ideas can be understood if they are explained incrementally. This doesn't just apply to lofty concepts or ideas. Mundane mechanical wonders can be explained incrementally as well.
Take the sets of gears called a differential. It connects three rotating shafts. Think about a power train from a car's engine and a pair of wheels. The differential is the mechanism in the middle that takes the power from the engine and allows both wheels to turn.
But the wheels can each turn at different speeds. Which seems to be a neat trick to pull off. I certainly had no idea how a few gears can do that.
It turns out that in the 1930s there was a short movie that described the gears and, step by step, explained how they work. Spend a minute or two enjoying the synchronized motorcycles and in no time you'll be shown the basis of what seems to be a complex bit of mechanical engineering.