The following is excerpted from the book Net Smart, by Howard Rheingold.
Twenty years ago, I coauthored a book with a scientist who studied sleep and dreaming – specifically the kind known as “lucid dreaming” in which you realize that you are in a dream state and begin to direct it. While writing the book, I needed to train myself to recognize that I was dreaming and then seize control of the plot. The method my coauthor, Stephen LaBerge, suggested worked well: I wrote the words “Am I dreaming?” on a small card and put the card in my pocket. Throughout the day, at least once during every waking hour, I pulled the card out, looked at it, and thought about the question. About three weeks into the exercise, I pulled out the card on an otherwise perfectly ordinary day and noticed that the letters seemed to scramble to get back into place when I looked at the card, as if the letters had been loafing. I had trained myself to question whether I was awake or not at least once an hour, and without consciously intending to do it, I started reality testing while I was dreaming. Although everything and everyone around me looked real, I decided to test my perceived reality by pushing off the ground with my toes. When I began to float above the ground, I realized I was dreaming.