Wow, this is exactly me too. I usually realize halfway through the semester that I competely forgot about a class I was in. Scares the crap out of me every time.
I also have the nightmare where you realize you have been forgetting to go to a class and it's time for the final. I also sometimes can't find the building. And sometimes I'm naked or in my underwear.
I guess I didn't appreciate my last ever final. I took no finals my last quarter (profs could let you out of the final if you were passing and you were a graduating senior and mine all did. I didn't know they all would the previous quarter). I do remember the great feeling of relief when the last final of the quarter (or better yet - spring quarter) was over and you'd accomplished another year of college.
I remember being VERY pleased and relieved when I opened up the letter saying I'd passed my PE exam.
Retirement was the best ever. Never having to get up and go in before dawn, fighting traffic, bad weather, alarm clocks was a great great feeling.