My former students occupy such important spaces in my life

There have been so many unexpected benefits to my teaching career, but none have been more surprising than the lifelong relationships that I have established with so many of my students.

I first got to know these people as seven or eight or ten year-old children, and so many of them are now adults who occupy such an important space in my life.

My wife posted this on Facebook last night about one of those former students:

Kate, babysitter extraordinaire and former student of Matt (grade 3) and mine (grade 5) just sang a lullaby over speaker phone to Charlie who wouldn’t go to bed without hearing a song that only she knows. Can I just tell you how special it was for me to hear a kid (well, not anymore) who I taught 12 years ago when she was ten sing my little one to sleep? (The answer is: pretty damn special.) Kate, thank you for making Charlie’s and my night.
— Elysha Dicks

Not every teacher chooses to forge such close ties with their former students, but I can't for the life of me understand why.