Which is your favourite topic in maths?

Which is your favourite topic in maths?

Mine is Calculus (and Differential Equations).

C1-4 would be the easy answer but incomprehensible outside the UK (Giggle). It's done at A level and does a bit of everything really but no stats which I despise

From the US system I'd pick a ghastly amalgamation of pre-calculus and trig

I have not much experience in maths but on this moment my favourite topic is also calculus, linear algebra is also very interesting but in my opinion much more difficult.

I loved using generating functions, it's a really good tool for solving recurrence relations.

I liked advanced linear algebra a lot (even though I don't think it's easy), analysis caught me in its difficulty and beauty and somehow even if I haven't studied anything further yet geometry/topology keeps me interested.

To pick one is criminal, but it would probably have to be series and proofs.

Quantum computation, though that's more at the intersection of math, electrical engineering, computer science, and physics.