I am not an expert Lisper myself, but to understand Lisp's power I'd suggest to write a basic parser of maths expressions (to evaluate things like "2+3*4-7+log(

I am not an expert Lisper myself, but to understand Lisp's power I'd suggest to write a basic parser of maths expressions (to evaluate things like "2+3*4-7+log(100)") - the language you choose to write it doesn't matter, it can be a Lisp or not. Doing that will require you to deal with the AST of expressions you are parsing. Then, you can try to tweak a bit the evaluator to optimize it. Doing so will make you manipulate AST, and since LISP is his own AST, you become aware of what you can do with it.