Thanks to whoever pointed me toward the Icon language. That led to the Unicon extension which may give me a better understanding of FP than Lisp/Scheme. I think the big legibility issue is in the lack of intermediate variables. In Lisp people seem to be encouraged to accrete code into a single nested expression rather than defining intermediate quantities. Even though the intermediate variables aren't required at runtime, they document and isolate parts of the code into legible chunks. In this respect even Forth makes more sense to me. I just can't visually digest an s-expression longer than half a line.