Individual functional programming techniques may become interesting to you as you become curious about some implementation details— you might read a bit about 'fixed point recursion' after you chat with some people about how overlays work. But you don't have to think of yourself as a functional programmer to make great use of Nix or even to help solve technical problems in Nixpkgs.

I think some folks hear all the FP talk surrounding Nix and don't realize that there's a lot they can achieve and contribute without being FP wizards. And that sucks. I hope that the ecosystem feels increasingly welcoming to people like that as the documentation and UX continue to improve.