haha I have one frequently where I am in college, and I totally forget that I have enrolled in this History class (it's always history), and then I remember at the end of the semester, right before the final exam. 
I rarely dream,but man, those freaking college exam dreams.. I've had one for over 10 years. Its an organic chemistry test with all of the chiral compounds on it. The thing is the compounds are like nothing I've ever seen before and I can't remember the basics of what I'm trying to do. The only equation I can remember is Na + H2O2 = NaOH + OH (its a bullshit equation that has nothign to do with chirality). The kicker is the chiral compounds when arranged correctly spell out the unidentified tissue on the drawing of the equine testicle (That fucking test was the only quiz I ever flunked in veterinary school---and I flunked it good and to this day I don't know why I wrote down some of the answers I did for it. I came back and got the questions right on the practical, but that quiz killed me).
Another one I have is this tantric sex dream.... yes, I know I'm male, I've had sex dreams as long as I can remember. But the thing is all of the women in it are my wife. Usually there are twins, sometimes triplets and one wild night there were sextuplets. That was a good dream, until my wife slapped the crap out of me for moaning and grabbing her breast. Then I woke up. The weird thing about that dream was when I had it as a teenager, the women never really had a face (Ok, I was more concerned with other areas of their anatomy, but I don't remmeber faces). About 6 months after I met my wife, the face was hers and its been that way ever since. I can't remember the women in that dream ever having a face other than hers. I'm not sure what that means.
The final recurrent dream I have is one where I get stabbed. I'm walking down a back allyway and this guy steps out and asks me for my money/wallet/computer/wedding ring. I tell him no, I don't have what he's asking for. He then starts cussing me in Spanish (or Greek--I'm not sure) and pops a knife. A fight ensues with me ultimately getting stabbed in the abdomen. Up until last month when I injured my abs, I never felt pain from getting stabbed. Then I had the dream last month and I literally woke up screaming. Its weird.....The thing is when I was in highschool I ended up in a knife fight where I got cut. I've always thought it was just reliving that experience, but the feeling the pain was weird.
The final dream I have is one that so far doesn't end but its way too vivid and fucked up. I'm working at a zoo and there is a big cat escape. Basically I then start hunting the big cat (It can be a lion, a tiger, a jaguar, or a leopard, it varies) with a dart rifle to keep it away from the school that is along the property of the zoo. The thing is my dart gun is made from a water balloon and a hollow bamboo pipe. We are using Etorphine (a highly concentrated narcotic which isn't used in big cats as an anesthetic. Its also very dangerous for human use with only a few drops on the skin in theory being capable of killing a human) to immobilize the cat. I go through the brush to the cat which is staring at me when I realize that not one, but two of them have escaped and I'm the one being hunted. I try to reload a dart so I've got a spare, but everything you can imagine goes wrong with the dart, from the rubber stopper sticking to me not having enough drug, to me getting the Etorphine in my eyes, to the dart not pressurizing. The whole time this big cat is hunting me, stalking through the woods with the other one just sitting there staring. I put the second dart behind my ear (why I dont' know) and proceed forward to dart the cat that is sitting there. I get within a few feet of it, and shoot it with the dart gun. When the dart lands, it doesn't move. Its then that I realize it was a stuffed decoy set there by the cat that was hunting me so I would waste my dart. At that point the cat jumps out of the brush and attacks me. I try to beat it with the bamboo pipe of the dart rifle because I can't get the thing reloaded. Then there is an elephant crashing through the brush, which distracts the cat. I stab the cat in the ass with the Etorphine dart, and watch it slooooowly discharge as Pumba and Timone sing the "No Worries" song from the Lion King which is followed up with Timone asking me if he dressed in drag and did the hula if it would help save my shit. The cat turns on me and pins me to the ground and I wake up.
I'm really not sure what all of that means, but I'm a bit afraid to find out the ending.
