It's Hard, but You Can't Take it Personally

The other day I was subbing for another teacher during my conference period. Since I got the call late to sub I was about 3 minutes late. This class followed a 20 minute "nutrition break" plus a 6 minute passing period to get to class. When I arrived the 18-20 freshmen Algebra students were standing outside the locked classroom door. Once inside, I told them that while their regular teacher might let them listen to music or eat during class, "unplug" and put away all the electronics and food. I reminded them a minute later as some were slow to do this. Also, by this time they had about 30 minutes to eat something, they still shouldn't be eating chips (Flaming Hot Cheetos seem to be the current favorite). I am now starting to call roll and take attendance and I notice a boy is still eating chips from his bag. I assertively said to him from about 6 feet away while making eye contact, "didn't you hear me, you need to put your food away."
"I'm not done!",
he replied angrily as he reached for another chip.

"Go outside and stand by the door, I will be with you in a minute", I told him.
He left and about 20 seconds later I looked outside and found him about 120 feet away nearing the end of the hallway. "You need to come back, stay here", I said loudly. He turned when I said this but kept walking away.
I had to call the dean about this boy's behavior and talked to him at the end of the day again. The boy was suspended for later skipping another class and also from not cooperating with another teacher who had made a request from him.
It bothered me initially and I thought about it periodically until I went to bed that night. It was then I realized that his aggressive and disrespectful behavior with me was not really about me, but more about him and what was going on in his life. It was then I let it go and found myself ready to sleep without worry.
We only see the surface of these kids, but we never see the problems at home which could involve various forms of abuse, neglect, divorce, life threatening illness, death, incarceration and more. Each student also brings with them their collective experience with all their teachers in the past, good or bad. Or maybe this kid is an A student who was just really hungry that day and had low blood sugar. Anyhow, misbehavior in our classrooms is rarely about us. It's sometimes hard to do but we have to let some of it go and not let it bruise or trouble us.
Also, if we are really motivated, we can dig deeper on another day and see if we can uncover the reasons from this maladaptive behavior. At the very least, it's probably worth a referral to the school psychologist to let them do their job.