It's really a shorthand for writing lists - sexp's are lists, so can use the same syntax. Macro's in Lisp are essentially "just" functions where the arguments

It's really a shorthand for writing lists - sexp's are lists, so can use the same syntax. Macro's in Lisp are essentially "just" functions where the arguments are un-evaluated - you can use all the same functions etc... Writing a simple Lisp interpreter is really quite educational - when you add macros and quoting into the language, you suddenly have a realisation at how simple it is.