I came from a procedural background, then adopted object-oriented programming, and now I am very enthusiastic about functional programming. Is this kind of an evolutionary path as a programmer? Or am I just late to the party?

And what paradigm follows?

I did the same, much prefer OOP now that I'm into it but I remember back in the day everything I did was procedural

Next is quantum :O

Right there with you.

OOP is great but there are cases it's counter-intuitive, if not troublesome to implement. for example fetching network requests and transforming streaming data. I'm new to the whole FP scene as well but find it very interesting. I thought these mathematical expressions are for educational purposes only :P

You might want to look at RxJava or RxPython etc. It's used in Retrofit if you're developing API library.

The next is array programming/vector programming. Languages like J.