My intro biochem class was team-taught. The last professor taught the unit on genetics, which I'd studied in various classes about 4 times before biochem. Yet after the first three lectures, I realized I couldn't name a single topic we had discussed, and was in fact getting DUMBER. Everyone must've had the same epiphany, because 100 of the 150 students in the class stopped going (myself included).
Enter the final. He's angry. So we're told the final will be multiple choice, but little do we know it's not the good kind. It's the type with 7 possible answers (A-G), where answers A, B and C give single responses. But then answers D, E, F, and G are combinations of A, B and C (i.e., E = A and B, F = A and C, etc). The average on the final? An "F" -- and this was NOT hard material. Talk about killing interest in a subject.