2015 marks the centennial of Einstein's discovery of general relativity, a theory that represents an unprecedented combination of mathematical elegance, conceptual depth and observational success. The talk will begin with a brief account of this discovery and the birth of modern cosmology, then discuss the concept of black holes and the major role they have come to play in astrophysics and fundamental physics, and finally explain the notion of gravitational waves. Through numerous historical anecdotes, the talk will illustrate a century of successive triumphs of general relativity and explain why researchers, who study general relativity in a serious manner, continue to be enchanted by its magic even a century after its discovery.