because, i guarantee that it's not beyond our comprehension. at some point the author was a 2d-er that read/did something and had their understanding expanded. so... do that for us
I remember playing with call with cc, or creating a flow programming language, thinking in higher order, etc..
I clearly do not want to work with lisp, and many of those concepts can be used in other languages without too much effort now (lambdas, map, filter, reduce,... Among the most common and useful).
I think learning lisp is nice as it helps explore interesting areas of programming on a mental level. I can't stress enough how it can wrap your mind sometimes.
Will it help you program faster and bug free? Probably not, will it improve your mental model of programming languages, probably. Will you enjoy learning abstract things, if you like solving math puzzles, probably, otherwise probably not.
It's hard to express the 'powers' it gives you, it's like spending much time thinking about simple things that usually you just use without thinking about.
As a crude example, the scope of a variable shared between two lambda function that is not shared with the global space.
Sorry that I don't have a specific example in mind, I feel like the 'power' is just spending enough time thinking on complex things.