Not sure if you're referring to cube theory or just the ability to solve... If it's the former, almost anyone can learn to solve a Rubik's cube in a few days (albeit in a non-optimal fashion). It's a matter of learning a handful of algorithms for each layer then executing. It can quite a fun way to keep the hands busy while thinking, like crocheting or knitting.
I am talking about cube theory. Solving it isn’t that hard unless you want to be super efficient. But formalizing it in way you can then reason about seems very hard to me.
I remember after a few weeks I figured out a move that could swap two pieces without other changes or something like that (don't remember the details). It was horribly inefficient but it did the job.