You saw one example, misunderstood it, and jumped to various unsubstantiated conclusions from there. So there's not much to reply to here, except to point out that the annotations are optional, and the following is an equally valid way of writing that same function in Pyret:

  fun square(n):
    n * n
  end

[Speaking of beginners and new concepts and so on: they wrote functions in school in math all the time, and didn't write `return` there either.]