The most realistic dream I ever had involved dreamed sexual relations with my roommate.
I don’t want to talk about it.
(in reality - YOU don’t want to hear it… 
)
For about 3 years after my mother died, I had recurring dreams that she would show up. I’d always say, “Mom! We thought you were dead!” and she would tell me that there was a miscommunication, she’s actually all right. I would then think how excited my father would be to see her again, how relieved he’d be to find out she was still with us. I’d be about to call him when I’d wake up.
Every single time I woke up from those dreams, at first I’d be all excited to think that she was alive. Then, of course, after a few minutes, I’d remember that she WAS dead, and then I’d feel like crap all over again.
I have also had hynagogic and hypnopompic dreams where I was awake but paralyzed. Either someone/something was in the room, intending to harm me, or scare me, and I’d want to scream or move, but couldn’t. Those were no fun.
Also, ever have a dream that someone did something to you (like, boyfriend cheated) and when you wake up, you’re mad at them? Puts me in mind of a quote from Reservoir Dogs: “You shoot me in a dream, you wake up and apologize.”