My mathematical training is mainly from the category theory school of thought (more specifically the set theory inspiring category theory school of thought) and I have to say that I find it difficult to move from category theory to functional programming. I think it's because mathematics is more about a way of thinking than about the tools.

For example, reading category theory introductions meant for programmers to me is confusing, even though I know the mathematics already! I still need to get around to Milewski's book which looks to be dually useful as "functional programming for category theorists".