Every so often I pull out my copy of Stick and Rudder, the classic explanation of the art of flying by Wolfgang Langewiesche. His explanation of the glide line makes a great reference for attitude flying.

Most adults who grew up in the late 1940s are familiar with the whooping cough epidemic of 1949 that killed dozens of children in the United States. It was a highly contagious disease that terrorized parents for many years. Before the days of vaccines, school children suffered through mumps, measles, chicken pox, whooping cough, and polio. I was no different. I endured all of them, except polio.