Xi-Ren Cao (SM'89-F'96) received the M.S. and Ph.D. degrees from Harvard University, in 1981 and 1984, respectively, where he was a research fellow from 1984 to 1986. He then worked as a consultant engineer/engineering manager at Digital Equipment Corporation, Massachusetts, U.S.A, until October 1993. Then he joined the Hong Kong University of Science and Technology (HKUST), where he is currently chair professor, director of the Research Center for Networking. He held visiting positions at Harvard University, University of Massachusetts at Amherst, AT&T Labs, University of Maryland at College Park, University of Notre Dame, Tsinghua University, University of Science and Technology of China, and other universities. I have the privilege of participating in the development of the discrete event dynamic systems (DEDS) almost starting from its beginning. In this talk, I will review its brief history and major results, in particular in performance optimization of DEDS and its extensions. I will share my experiences on and views on how a research field is evolving, what are the important features for a researcher, the relations between theory and applications, intuitions and mathematics, peer recognitions and “cold stool”, and many others.