Strangest Dream...

Today I got the strangest dream ever ..
In my dream I was sent back to past, the year is still 2002. And I still got a bunch of friends, and the dream took place in my old college classroom. The class were crowded with friends and colleague, it was almost felt like heaven. Being with friends and everyone that I knew, but suddenly the class grew quite. I knew the class was about to begin.. I could hear the Professor footsteps approaching from the hallway.
My friends next to me softly said
" Have you finish the task given two days ago ?"
with a great confusion I asked
" What task? I just got here, how would I know there were any assignment ?"
" Just got here?, what do you mean you just got here? seriously you are in big trouble if you hadn't finish !"

My knee is shaking, the Professor is getting near and i had no idea what is the assignment. Everyone in the class already finished the task and had satisfied look in their face.

Soon I was wake up, with sweaty shirt and gasping breath. For a while I couldn't think normally for I still sat beside my bed and think really hard..
" What was the assignment ? How could I forgot ? What happened?"
Eventually I regained full controls of my mind. I had graduated from college years ago, but still I wonder if the dream had any meaning or not.
What was the assignment ?

picture inspired by hotel dusk:room 215