Today marks the tenth anniversary of the day we lost Carl Sagan. He was a true skeptic; a man whose mind was open to possibilities, yet able to cut away the chaff of pseudoscience and blind alleys. Even when facing death -- a slow, painful, wasting death -- he was able to turn it into a series of lessons on science, medicine, and critical thinking. Many people, perhaps most people, would have clung to any idea, no matter how irrational, to make themselves feel better. Carl didn't do that. He couldn't. He not only relied on science, he reveled in it. To celebrate the man, I am writing this essay as part of the Carl Sagan blogathon. I'm very interested and excited to see what others have written (