Grades in College

It suddenly hit me what it is the letters must stand for in the American College grading system:

A for Aced
B for Brilliant
C for Conservative
D for Deficient
E for Excuse Me?
F for you FLUNKED!
W for Wuss

Oh, and I managed to get my math instructor to crack up today; I asked him what “i” (square root of negative 1) said to “Pi” and what “Pi” said back - “Be Rational!” “Get real.”