Sense and nonsense is abound in human performance technology (HPT). There is no single cause of the abundance of nonsense. However, there is a reason that nonsense is more abundant than sense. The reason is that any principle has a specific domain of applicability. Within that domain it is sense. Outside that domain it is nonsense. Some principles, especially in physics, have a very broad domain of applicability. Some principles of HPT also have a very broad domain of applicability, but that is weak consolation if only a few people know these principles. There is so much nonsense in the field not because people are collectively ignorant, but because they are individually ignorant. That is a reason for personal humility and shows the value of collaboration. In this article, the author presents six statements that make sense in one context and nonsense in another.