A fully bracketed prefix notation is unambiguous. It requires no knowledge of precedence rules. Small children can learn it. Your editor can indent it in a consistent way, no matter how you break it into multiple lines. You're almost never left wondering what element of the program is a child of what other element. You know the argument position of everything; there is no guesswork. If you misplace a parenthesis, the wrong indentation clues you in. Working with Lisp syntax requires few brain cycles; therefore, the syntax per se doesn't demand high intelligence.

If you can fog a mirror, you can probably edit Lisp.