I suppose you could make some generalisations based on how many people report on how dreams work for them, but I would still take any psychology textbook that claims authority on dreams with a box of salt.
Had a dream, was kind of morbid, where I was in a big mansion for some reason I forgot, with a bunch of other people and Hannelore. She was scared because people kept showing up in unexpected places, often behind her, but no one meant any harm. Still, we were in the kitchen so she grabbed a massive cleaver, like, broadsword-sized from somewhere for protection. Then she ran off, and I heard her scream in the next room. I figured it was probably nothing, but I grabbed a similarly large knife too, just in case. But when I got there, I saw a girl in a mask and a hood who was obviously a psychopath, and that was why Hanners got scared. I told a guy to warn the other people in the house about this dangerous person, but he was too busy running away in terror to do that. The girl grabbed Hanners like she wasn't even holding a sword-sized kitchen utensil and then she threatened to cut off her fingers. I told Hannelore to scream, but she wouldn't. I tried to stab the girl, but I was afraid to because of her threats, and she kept distracting me by talking about something which I also forgot. Moments later she did start cutting off fingers, which she did so quickly that it was like cutting vegetables. The girl let Hannelore go, who then put the amputated fingers in her mouth - probably because I know that preserves appendages for surgical reattachment, but I didn't realise it at the time - and then the masked psychopath was about to do the same to me. So I screamed like a girl, realised I had been a girl the entire time, and woke up. The end.
That was two days ago, and last night I bought a bottle of soft drink that was only filled 1/10th or so, and when I looked at the label it said "500 mm3". I tried to convert 500 mm3 to ml, but I couldn't before the dream faded into something else.