"Doing Superb" joke

A college student sent the following letter to her parents:

Hi Parent!

Today i September 15. I'm doing superb in school (or, should I say, college). The teachers are great, my roommates are great, and I'm having a super time! All I could use right now is a little cash.

To which the parents responded:

Hi daughter!

Nothing happening on this end. Something's wrong, because you know, we got this letter in November. I am not worrying about anything down here, knock on wood huh?

Your loving parents, Norden and Morden Finkelstein.