I'm trying to work my way through a textbook on calculus on manifolds. I work more than one job-not math related. I have no one to ask questions in person. So I'm very grateful for this resource , and I don't want to impose upon the people who volunteer their time answering my questions. What should I do when I need more than a hint? It sometimes seems to me that I have missed something basic that responders assume I already know or understand. Thank you.