One of the most emotional moments for me is when a Ph.D. student passes the defense. My Ph.D. students spend years with me in my lab. We share much more than just writing papers. We see each other almost every workday as long as I am not traveling. A page is gone and a new page is coming when a defense is done. One the one hand, I am really happy and excited that they can move on to their real careers. I am sure that they will be successful and fruitful, in career and in life. On the other hand, I really want to retain each of them. They are my academic kids.
I just experienced such an emotional moment last Friday. My another Ph.D. student succeeded in her defense. Congratulations!