Requirement Gathering is I believe the most difficult task and to put the requirements in user stories so that others understand them is even more tricky. When I say others I mean the developers who will develop them as well as the testers who will work on the developed features.
I have been facing the same issue at work and I am very sure many of us do when we read and understand the requirements in the form of user stories. In case of specific customer scenarios sometimes it is challenging for us to relate it to the practical usage that will happen @ the customer site. How will he use it, who will use it, what could be the possible conditions/pre conditions...
Sometimes it does happen that you come accross a customer scenario which is difficult to understand and visualize. In those situations if the requirement is written with : Given-When-Then it really helps.
