myn was the same
from a class of 12 i was 3rd last to leave with the 2 smartys staying to do there best, it was a very short exam and i tink they botched it up due to the fact that its only 2 years old
sound and light polution could be one, on late nights u might be workin late and have lights onkeeping people awake, or u might be playing cs with the sound to high......