After you first experiment with Media Queries and find out how easy they are to use, you may start thinking about some of your favourite web sites, and imagine how they would be made responsive. You may suddenly find yourself thinking that everything should be responsive; hell, you would make your family and friends responsive if you could!
But you need to take a step back, and exercise restraint: depending on the context and purpose of a project, it might be better to not go down the responsive route at all, or at least limit it. (…)