Difficult clients are always there. You should face such clients at least for a decent duration of time to handle the scenarios/issues they have given. It is how, you will learn the subject/requirement, deliver it and resolve the situation. If the client is difficult intentionally, its the other side of the coin. However, you need to please the client by adding your suggestions which will be a selling point for their business. Your experience counts here and adds credibility to your profile. As long as your lead/manager safe guards you from the difficult client, it is fine. But, when you are directly dealing with the client on some specific requirement, its your responsibility to keep your lead/manager informed when taking the step forward.