Eric Raymond's famous words: "LISP is worth learning for the profound enlightenment experience you will have when you finally get it. That experience will make you a better programmer for the rest of your days, even if you never actually use LISP itself a lot."
I've heard echos of this applying to functional programming languages such as Haskell and OCaml.In Joshua B. Smith's book Practical OCaml he says:
Using OCaml will also make you a better programmer. This may sound like snake oil sales pitch, but remember that programming is about algorithms and data structures. Learning a new programming language expands your understanding of these concepts, resulting in a a better programmer in you.
16 October 2007
Quite possibly: but remember that most of the point of the Lisp family is the way they allow code and data to be treated interchangeably, allowing meta*-programming in a way that Haskell and O'Caml don't.
There are many languages out there that can make you a better programmer :-)