I've been listening to the 4-Hour Workweek audiobook lately and absolutely loved this quote:
As to methods there may be a million and then some, but principles are few. The man who grasps principles can successfully select his own methods. The man who tries methods, ignoring principles, is sure to have trouble. — Ralph Waldo Emerson
I was recently chatting with someone about Agile and how it really only consists of principles so it can't really fail. What fails are the methods that people use to implement the principles.
If you don't actually take the time to grasp the principles then you're really just cargo-culting.