Each time as fun. If you know Lisp you will instinctively convert any syntax back to S-expressions anyway because that's how things will eventually work anyway

Each time as fun. If you know Lisp you will instinctively convert any syntax back to S-expressions anyway because that's how things will eventually work anyway and because you can't think of Lisp macros otherwise. So, the syntax becomes a burden, and thus you settle for the minimalist, easiest way to denote trees. Parentheses.