People who've befriended "the quiet kid" in school, what things did you wish your other classmates knew about them?

People who tried to make friends with the "quiet kid", how did it go? What's the quietest kid you've ever taught lessons to? High scorers, how'd you feel about your performance on the exam before you got your score? Were you surprised? Did anyone feel like they bombed it but ended up doing well? Or did it fall in line with what you were hoping for?