One of my students from my organic chemistry class in Peabody two years ago just sent me the following:
hi mr. bigler, i don’t know if you remember me but its $FORMER_STUDENT and you taught me in organic chemistry and i just want to say thank you because i am in the class right now and i got 100s on my first 2 quizzes and i am just leaps and bounds ahead of other students in terms of understanding. so thank you again! and i hope all is well
I replied, “Of course I remember you, and you just made my day!”