I can't find the source of the quote now (it was a Part III Introduction to Category Theory paper, I think) so I might have remembered it incorrectly, but Peter

I can't find the source of the quote now (it was a Part III Introduction to Category Theory paper, I think) so I might have remembered it incorrectly, but Peter Freyd once said that the purpose of category theory was to prove that that which is trivial is trivial for trivial reasons. It certainly helped me as a mathematician, because it tells you what's actually hard and what is merely complicated. A while back, I wrote the final section ("Why is the product interesting?") of https://arbital.com/p/product_category_theory/?l=5zv https://arbital.com/p/product_category_theory/?l=5zv, which attempts to explain one part of why CT is helpful.