I was a college math major. Category theory wasn't one of the offered courses at my college, so I didn't study it specifically. But I didn't get through any of my math classes without working the problems and proofs, and without having a teacher to help guide me through the material. It can't be read like a book. At least that's my experience.
And as I get older, being interested in the topic helps more and more.
As a counterexample, I have self-studied queuing theory, extreme value analysis, combinatorics, generalised linear regression, etc. and had no problem with it.
Category theory I just can't get through. Either it does not fit with my brain or I fail to see the practical implications, but something makes it not stick.
(Curiously, differential equations (beyond the basics) are in a similar spot for me, even though they are obviously immediately practical in a huge number of areas!)
This oughtn't be super surprising, even the DE comment at the end - people do just have bits of maths they gel with more than others!
Even so, CT is not easy to motivate without a lot of experience in a few specific areas of maths - it's definitely a very "meta" subject (even though a lot of these blogs pretend it's super applicable to everyday engineering) and is a very different lens from the maths taught up to that point.
And as I get older, being interested in the topic helps more and more.