There are a few things I can't do in short notice. I can't find you meeting space in our building after 3, I can't have a meal catered. I can't get you an AV person for your lecture. I can't order lunch for you (especially if you don't tell me what you want!).
Now, I'm usually very good at my job, but some things I just can't do.
And when do I get asked to do these things? When the professors forget to tell me that they need something. They forget, and I get panicked emails over night about said things. And it's up to me to fix it.
Sometimes it just doesn't get done. And I feel awful.
It wasn't my fault.
I need to let it go.