When I first read The Teachings of Don Juan it hooked me completely. Although a lot of people ascribed Castaneda's story and his description of Don Juan to a mere figment of the imagination, the concepts presented by Don Juan nevertheless "felt right". The complexity of his teachings and the unusual logic to it cannot in my opinion be a product of Castanedas vivid imagination.
There are some truly hilarious passages in the books, especially when Don Juan and his sorcerer companions "tricks" Castaneda into seeing the world differently.
Castaneda's attempts to explain the things he's experiencing rationally makes the stories all the more fun to read.
If you're a seeker on a spiritual path and keep an open mind, this book might introduce you to the most efficient, disciplined and difficult path known to man.