It's brilliant. By gradually building up to it, I started to really understand recursion, the power of lambdas and closures, etc. I also started to get Lisp and

It's brilliant. By gradually building up to it, I started to really understand recursion, the power of lambdas and closures, etc. I also started to get Lisp and Scheme in the process. It's a great book, well worth it and if you're venturing out into the Lisp world, I strongly recommend it. If you're not into Scheme, I believe the book also contains equivalent Common Lisp code.