I know it sounds silly, but one of the things that I particularly like about Lisp is the lack of the shift key. Notably, you can use identifiers-like-this. Yea, I haven't made the plunge to move () off the shift key, but I barely notice it compared to having to alwaysTypeLikeThis or type_like_this.

The keyboard fatigue adds up, and it's just an intangible I like about the language.