And how do you figure out what the requirements are? In my 10+ professional years, I have never gotten requirements by asking for them. Almost always I had to show my interpretation of what I think the requirements are, and use the feedback I got to define the actual requirements. The quickest way to get there is by iterating.
You don't ask for the requirements. You ask what they're trying to do, or what problem they're trying to solve. Sometimes I have to ask "where is this data going" or "what do you expect the end result of this to be".
Not disagreeing here but whatever question you ask, you will only get the final answer _after_ you have implemented it, almost always after several iterations.
