Philosophers have long proposed that there is no objective reality. And now science agrees — at least as far as our personal experiences are concerned. Perception is the process of interpreting our present environment through the lens of our past experiences. Everything we sense, think, feel, and even remember, actually arises in response to a combination of what is currently happening and our stored long-term memories. In this edition of Two Guys on Your Head, Dr. Bob Duke and Dr. Art Markman discuss the evolutionary advantages of flexible perception, and how this process can influence both our behavior and modern day society.