Are you going to the moon?

It is a famous saying of a Mathematics teacher in La Salle College, Hong Kong. He used it to express his dissatisfaction on students who packed their school bags before the bell even rings. In normal conditions, it can be used to question someone who is going away to obviously nowhere for the purpose of avoiding something deliberately.

30 secs till bell rings, random student packs his bag.
Teacher: are you going to the moon?

there you go again

Ronald Reagan quip, it's basically a come back for when someone is speaking nonsense.

Type an example of how it's used in a sentence, geez ? "There you go again"