I do rarely give evaluations, however, this book is so outstanding with presenting a really difficult subject matter that I want to explicitly recommend it. Math textbooks even meant for a non-studying community almost always place rigour in the driver seat. This book, however, shows that developping first an intuitive understanding is the better approach. Working with graphs and pictures is so important as a basis and algebraic tools are by far better digestible then. I did not put my hands on differential geometry when I studied physics 30 years ago  and I did not expect to get close to General Relativity some day. Now I see it is doable. In a future version of the book, Tensor Algebra could be replaced (or added as Act VI) by Geometric (Clifford) Algebra.