#3 When former students come to visit
I love it when graduates come back to visit, even if it is students I was not particularly close to. It is amazing the transformation they go through in the 1st year of college. Last week some of my former students showed up randomly and one ended up spending nearly 2 hours just chatting with me during my classes. He is not really that different than when he left, but his confidence level is so much higher. He just went on and on about the different things he was doing, the people he was meeting and even the places he was traveling to. I was only his teacher for 1 year, but I am proud of the man he is becoming.
#4 When a plan comes together
One of the philosophies of the Flipped Classroom is to increase peer teaching to allow the teacher more interaction with all members of the class. In my classes, there is much more collaboration than there is peer teaching. But, in one class I have three guys who just fight with each other over who has the right answer. And when I say fight, I mean disrupt the entire class as they argue back and forth as to who has the best method for solving the problem. Normally, you need to squash this kind of behavior, but after the argument they sit down and explain the solution to each other. It is so amazing to watch this sudden shift from combatants to teacher to combatants again. I love it when a plan comes together.