The “Last Lecture” was written in February 2004 for presentation at Mortarboard’s March 2004 annual “Last Lecture” series. Mortarboard is a national undergraduate honor society and each year it sponsors a last lecture series at Cornell in which two professors are asked the following: “If you were retiring tomorrow and had a half an hour to give a last lecture to your students, what would you say?”  As the attached should indicate to you, I took the charge quite seriously. The lecture was written before we learned in August 2004 that our son’s brain tumor had begun to grow again and, that as a family, we would once again be facing a very trying time. I gave the lecture to my class to read that fall to explain to them why they would only see me on the screen in the classroom; I was going down to Washington, DC to be with my son and his wife while he was treated and would be teaching them from the Cornell-in-Washington Center. His hospital stay lasted almost two months and when I returned to Cornell a number of students told me that this lecture was the most important thing that they had read during their years at Cornell. So I now share it with my undergraduate students each year in the hope that the messages in it will be of use to them during their lifetimes.