It's good to care about getting good grades.
Jeff is a freshman in high school and has a lot of homework to do with little motivation to do it.
Jeff wants to enjoy his time in school.
Jeff decides to see how quickly he can do his homework, racing himself every night.
Jeff puts his homework aside and goes to play with his new high school friends.
Jeff gets excellent grades and gets a full-ride scholarship to a university after he finishes.
Jeff does terribly during his freshman year and those grades make it difficult to enter a good university later.