K&R is so clearly written that I was able to understand it as a sixth grader. (At least, I felt like I did; subsequent events later proved that I did not understand pointers, but I don't think it was K&R's fault that a sixth grader didn't understand.) That's why it's still being recommended and the much thicker tomes also purporting to teach the C language have been forgotten. It's probably the same reason that your copy is torn and tattered.