My almost nine-year-old said, "I don't want to go to school today! On Yom Shlishi we have a teacher that screams too much, and my ears hurt for the entire day..."
I said to her, "You are almost an adult! One of the differences between big people and little people is that we sometimes have to spend time with people we don't like. Every time you do something you don't like because it is the right thing, you become bigger."
"Well, I don't want to go today!"
"Hmm... We'll have to push off your birthday by one day..."
"Okay, fine, I'll go. I want to be nine already."
(I didn't expect this to work.)