React, it's declarative way of doing things, and the functional programming methodology it prefers.

Realized how much I've moved on from for-loops and class/object instance to maps, filters and immutability/observers when I worked on a Laravel project after so long and found myself forced to do things in the, erm, "PHP" way, despite spending my initial year and a half of programming working exclusively in PHP.

Sure, there's Class Components and imperative techniques in React but I had blissfully settled into using the flexible nature of doing things enabled by both native JS and React, with hooks, Lodash/Ramda and (almost fanatically) pure functions