It’s been Back to School Week on my Facebook. Not only do I have a lot of friends sending their kids off, I have a number of teacher friends, thanks to the five years I spent in a classroom.

Even weirder, I’m Facebook friends with some former students who are now teachers themselves. I was thinking about the teachers I know when I sat down to write about “Short Term 12.” Mostly because I wanted to write about “Short Term 12,” but apparently repeating “ ‘Short Term 12’ is really good, go see it” 44 times does not a column make. So I’m going to talk about Grace (Brie Larson and, yes, the character’s name is a little heavy on the symbolism), who works at a “short-term” foster-care facility. The quotes are ironic — some of the kids have been there for years.

Anyway, Grace does what she can. She sprints after kids who make a run for it and has a linebacker’s talent for tackling when the situation calls for it. She deals with spit. She deals with blood. She deals with the emotional trauma of kids who have been told that they are not wanted. She does what she can to do right by them, and in that she is a success.

Grace’s struggles reflect what millions of highly trained, educated and dedicated people gear up for each year at this time. Larson’s face mirrors the decisions every teacher has to make. Which kid can I reach? Which kid can I save? Which unreachable kid do I sacrifice so I can save someone else?

I can attest that her struggles hit you hard when you’ve tried to answer those questions yourself. When you watch “Short Term 12” — and it’s really good, go see it — take a moment to realize that those friends of yours who are rereading “Beowulf” (AGAIN) and who are bringing the gerbil cage back to the classroom after keeping it all summer (AGAIN) and who are cutting out letters to label kids’ backpack hooks (AGAIN) most likely have a little bit of Grace in themselves.