Oh. That's why people spend 40 years in the classroom.

It's been three years since I started teaching. Out of nowhere, this shows up in my inbox:

My quick update: In Brooklyn college finishing my first complete year including summer classes now. I have been thinking and appreciating deeply your teaching of Functions when we were in class. I started off fall semester with a 2.93 gpa was unhappy with it i worked much harder in the spring and now have a 3.3 gpa. I am majoring in Childhood education teacher (grades 1-6). Hardest class in college: Psych Statistics. Lastly, I am still with my girlfriend for over 2 and half years now going strong.

 He almost failed out of high school. He's going to be a great teacher.