Prof. Ko, it was truly a honour for me to work for you as your assistant at the VP Office at CityU. Every day I learned different things from you, big and small. To me, you were not only a good role model and a great boss; you were also an extraordinary educator with a vision and a strong passion in teaching, and a selfless person with a big heart and a genuine soul to care for your students, your colleagues and your family and friends. The thought of not being able to see you again must be heart-breaking for so many people who know you and love you. But we will continue your positive spirits and move on with courage and your inspiration. Prof. Ko, we miss you so much, and we always will. You will always be in our hearts.