This is a soft/educational question and I'll flag it to be made community wiki.
A little bit of background, first. I am in my last undergraduate year, and I took a graduate course in category theory; this class really inspired me in a mathematical sense: I'm considering studying this at a graduate level and possibly doing a PhD in category theory.
The class covered elementary category theory up to elementary topoi/Grothendieck topoi and abelian categories (if you'd like to know the program more in detail I'll add it at request).
My question is essentially this: is my experience (or lack thereof) with this subject too narrow to understand the kind of decision that I'm making? I mean, I love the generality and the concepts studied in category theory because they give me a different approach to other subjects I'm studying (elementary differential geometry for example); I'm uncertain, though, as to what will be coming: I don't really know what studying category theory at a higher level involves.
Also, I'd love to know what books I should read to get a better insight of the subject. The book I got for class was Categories for the Working Mathematician and also (for the topos theory part) Sheaves in Geometry and Logic.
I really hope I made myself clear, but if I didn't just comment and I'll try to explain better.