That's great. Teaching is like this; those wonderful moments you don't forget sustain you through the bad ones.
I am not sure why people are so down on millenials. My sons are wonderful, caring people, who in many ways exemplify what you said about your students. They were (are) not straight A students, but they are extremely bright, articulate, and interested in the world. And some of their friends from high school (long past now... 10 and 12 years ago) have done fabulous things.