Pat Hanrahan and I were CS grad students at the University of Wisconsin Madison at the same time. In addition to being brilliant, Pat was kind, egoless, and infectiously happy. He was just a fun person to be around. I haven't seen Pat since grad school days, but I'm sure it's as true now as it was then!<p>Amusing side note: Brian Paul, who wrote the mesa open source implementation of OpenGL, was a Wisconsin grad student at the same time! He was in the meteorology department, in the building across the street from computer science.