“You need a reason to be sad. You don't need a reason to be happy.”
This quote, which D.J. says this after he is asked why he always smiles, is the ethos of Sachar's novel. No matter the circumstances you find yourself in, Sachar argues, always try to find a way to smile and be happy. After all, your life would be better off for it and you will be a better person for it too.
“It's funny how a person can be right all the time and still be wrong.”
Kathy says this quote when speaking about someone who doesn't like anyone. Kathy's point is that someone who claims to be right all the time and better than other people in their life can still be so brutally and foolishly wrong about every person in the world other than them being bad.
“They had never had a nice teacher. They were terribly afraid of nice teachers.”
The unnamed narrator says this about Mrs. Jewls' class, who are known for being zany and rowdy. Like many kids across the world, Mrs. Jewls' class is scared of teachers who appear to be nice and ultimately, normal. Teachers, in the mind of Mrs. Jewls' kids, need to be as strange as their students for the students to fully trust them.