Believing that you cannot play a warrior of grit and skill, whether fighting with mighty thews or quick strikes, unless you have a specific name written across the top of your character sheet. That is, being more attached to what things are called than what they do; being unable to accept something that functions in every way like what you desire because it has the wrong name, and only the wrong name, no other faults.
Hence: the cage of names. The name alone is more important than getting something made to do what people wish to do. If it has the wrong name, it cannot be right; and if it has the right name, it cannot be wrong. Both of which are ridiculous, but convincing people of that is like pulling teeth.