Hi, I am a Physics graduate and I am VERY mathematically inclined. (This does NOT mean I know a lot of math. My curriculum focused on experimental physics - which left me with a very keen desire to study all the mathematics involved - so I do need to start from scratch.) I would like to study and understand the Special and General Theory of Relativity in as much detail as possible. I do have some background in SR (I got acquainted with it A BIT), but I would like to understand not just "a lot more" but EVERYTHING there is to understand about both SR and GR. In other words, I would like to (re-?) start studying it from scratch, until I understand it perfectly (as "perfectly" as it is humanly possible). I have read similar discussions on this forum and the more I read, the more confused I became. I would be very grateful if someone could give me a detailed list of books that I can read in order to not only understand SR and GR, but also MASTER the mathematics involved (yes, the epsilon and delta of it). Please note that I am not looking to "get acquainted" or to "use shortcuts". I am looking for the hard sttuff, both the mathematics and the physics. (Yes, those books on manifolds, differential geometry etc.). I am definitely not looking for "summarized explanations" or for books that state theorems without proofs (whether physics books or mathematics books). If possible, I would also like a plan or "timeline" (e.g. "first study this book, then this other book etc.") that takes into consideration both the physics and the mathematics involved, and the respective books (good books / authors please). I just don't know which are the best books and in which order I should start. I know calculus (but not multivariate calculus), high school geometry including space geometry (but not non-Euclidean geometry), and I have some knowledge of vectors. I do "know" vector calculus but I only know how to apply a few theorems / concepts (del, div, Laplace) in a 3D Euclidean space, but not how to derive thosse theorems / concepts. (I am trying to give you an idea of my mathematical background). Please help and thank you very much in advance for your time and help.