Jack says that you do eventually get used to August's face, and that August is very funny and nice. He's also smart and lets Jack cheat off his homework. August even lied to a teacher to protect Jack when a teacher called them out for having the exact same answers on an assignment. Jack says now that he knows August, he truly wants to be friends with him. He was only nice to him at first because Mr. Tushman asked him to be but now, he'd want to hang out with August over anyone else in the fifth grade.
In Jack's anecdote about August lying, the boys' teacher would surely say that the kind thing would be to allow Jack to learn on his own rather than protecting him from making mistakes. This again illustrates how one's conception of what's kind or not changes and evolves as one matures and gains a more nuanced understanding of the world.