For years, computer scientist Larry Smarr, PhD, meticulously monitored and documented almost every aspect of his physiological being, down to the microbial diversity of his colon and its output — all part of an effort to better understand his chronic intestinal condition. He called it “quantified self.” When Smarr eventually needed part of his colon removed, he pushed the concept further: “quantified surgery.” With colleague Jurgen Schulze, PhD, he created a 3D model of his affected abdomen that his surgeon, Sonia Ramamoorthy, MD, could explore long before her first incision. Smarr’s successful procedure was a true “N Equals One” experiment, but also perhaps a glimpse at the future of surgery.