It's hardly related, but I once had a nightmare that I was back to high school and had to take an exam on integrals, but since I didn't know anything I just repeated to the teacher (who strangely was my college teacher) that I was an arts student.
When I woke up, I asked my friends who were studying engineering what integrals were, none of them gave me a satisfactory answer, so to this day I still have no idea what they are.