I first met Wenbo when we both were in the last year of junior middle schools during the award ceremony of the math competition in Harbin, the summer of 1979. I remembered vividly that he was the first place winner and gave an impressive speech at the ceremony. We met again during the training camps and at least one other math competition award ceremony at the Province level in the Spring of 1981 before we were both admitted to the mathematics department at Jilin University in 1981. We became good friends and often sat together attending classes in mathematical analysis (advanced calculus) and linear algebra. He was always friendly, exciting, and energetic. In addition to being a top student all around, he had many hobbies, playing bridge and soccer. Most of all, he showed a strong leadership to unit his fellow students around him. In the Fall of 1986, we both went to the states to continue our graduate study. He went to the University of Wisconsin to study probability theory. In May of 1989, I spend a month at the IMA and went to visit his family in Madison. We had great time together (we also went to see the city of Choicago together). The friendship continued to follow our footsteps and we continued to meet on various occasions in Delaware, Michigan, Beijing, Hangzhou, … We also kept each other updated about what we did and our plans in life and career. In fact, I spoke with him over the phone right before he left a recent IMA workshop in Minneapolis just a few days ago. I remembered clearly that he was as usual exciting and ambitious. Among other things, he did talk about his upcoming sabbatical which would include a short visit with me. We also discussed some research topics of mutual interest, namely stochastic PDE and inverse problems. It was a complete shock when I first heard about his tragedy on January 27, 2013. I could not believe it! Wenbo always appeared to be a strong man who enjoyed exercises, particularly mountain hiking, skiing. I will always remember him as a caring, loyal, generous, dedicated dear friend. His great achievements in mathematics and love to his family and friends will always be appreciated! May he rest in peace! Gang Bao