'And if you'd wanted to use a hash table, if you even knew what a hash table was, you'd have to write your own.' And just for the record, Common Lisp had hash

'And if you'd wanted to use a hash table, if you even knew what a hash table was, you'd have to write your own.' And just for the record, Common Lisp had hash tables since 1984 (and I guess Maclisp had them before that), but earlier lisp dialects had things like plists and alists.