If it's not going to matter six months from now, then it's not worth worrying about.
As teachers, we have so much on our plate that it's impossible to give every task the full attention it needs. I think it can be extremely difficult for first year teachers to keep from getting bogged down in all of the "little" problems that arise that seem like big problems. Whether it's a botched lesson, a negative interaction with a parent or administrator, or just an all-around bad day, these issues can bother us so much that they consume all of our waking (and sometimes sleeping) thoughts. While we can and should still take steps to make these situations better, I think it's really important to keep things in perspective.
If it's not going to matter six months from now - if it's not going to physically harm someone, if it's not going to cost me my job, if it's not going to damage a positive relationship beyond repair, if it's not going to leave me with a huge sense of regret - then it's not worth worrying about.
And because I think posts are always better with a photo, this is what I picture in my head when school stress is keeping me up at night:
I always tell myself "This won't matter one bit to me when I'm lying on the beach this summer!"