Connection of Mathematics

When you have long chains there are very few starting points—very few things need to memorize. In mathematics, you have very few that you memorize and the rest you deduce as you go through, and this chain of deductions is actually what's critical. 

The difference between math and other subjects; Math has fewer concepts but they're chained deeper. And because of the way that we usually learn when you had deep chains it's very fragile because you lose any one link—meaning if you miss a few concepts along the chain you can actually be completely lost.