I don't know about quirky, back when I first found out about it, it was surprising that I could read it without having written a single line of code on it. That's damn impressive.

To me, its type system and parsing nature are one of a kind, to be able to label everything as what it is

  [money!] is $12.53
  [tuple!] is 5.5.5.5
  [date!] is 16-Jul-2023/21:00:17

means the parser immediately parses and type checks everything, all while looking as human readable as possible.

It’s homoiconic, so the quirkiness serves very similar goals to, say, Lisp.