> Category theory is really the mathematics of abstraction
Mathematics is the mathematics of abstraction. That's all you're doing in math, from the beginning to the end. What's the same between "I have two sheep in this pen and five in that one" and "I have two apples in this basket and five in that one"? Hmm, you can abstract out 2+5=7, since it works the same in both contexts.
Everything in math is creating and exploring abstractions. The good ones tend to stick around, the bad ones tend to be forgotten.
Category theory is the mathematics of composition. How much knowledge can you throw away and create reusable patterns of composition? How many interesting things can you find by adding back the smallest bits of additional structure on top of that minimum? How well do those things compose together, anyway?