One part of Agile that most people miss when they first start is that there is a large focus on adaptability. New agilists get all tangled up in following the ceremony that they miss the underlying idea. This leads to teams that blindly follow the process without gaining an understanding of how or why it works.
For those PM's, QA's, BA's and developers that don't know how to "do Agile", adaptability is the goal. It makes everything make sense. PM's have lightweight plans, QA's get more involved in the testability of requirements, BA's collect stories rather than compiling books, and Devs code just enough to make something work.
If you're on an Agile project and you don't understand why you're doing something, just ask a simple question: "How does this make what I'm doing adaptable?"