Sorry, I'm not going to blame it on the school, but I've got a random work excuse for you!
I'm afraid I'm not going to make it to our meeting today, I'm suffering from Sudden Onset of Sudden Onset Syndrome. It's a real thing, I swear!
Don't worry, it's not my fault. It's just that I'm prophets of my own destiny, and destiny has called me to a higher purpose.
Maybe you can just tell John to cover for me?
Or, if you're feeling adventurous, you can generate another random excuse!