One of my reference experiences in that domain is trying to teach the idea of recursion to a bioinformatics freshman. It was right before the exam, after one semester of Haskell.

At that moment I understood why the university teaches that semester of Haskell. The idea of recursion is important and doesn't come naturally to people. It's just worthwhile to spend a semester with a language that most of the students aren't going to use afterwards because recursion is that important and that hard for students to learn. It's simply takes a few months to get that idea into a brain.