The way i look at it DC 's are just another part of the whole ‘me’, as in my complete being… Given the characteristics of people around me… after all, your whole dreamworld is build from influences from what you see IRL every day.
That being said; if you want to dream lucid, there is a part of you that thinks about making yourself aware of dreaming. I think it’s that part that tells you you’re in a dream, or leaves hints or whatsoever.
I’ve heard people saying it’s just a quick reaction of your brain, as soon as you figure out you’re dreaming, your brain processes it and a DC tells you you’re dreaming. Though i don’t believe in that, since i’ve had DC’s telling me i’m dreaming and i just ignored it, or just didn’t become lucid.
A while ago i was making soup (i never make soup ) and i was sturring it with a big feather (don’t ask)… so i tell my brother, who was also there, “Any idea why the soup is turning blue?” (The soup was real blueish, with blue clouds comming from the pan)
So he shrugs and says: “No idea, guess it’s all possible when dreaming”.
I then smiled and told him i’d return the favor sometime… i then turned lucid and went outside, noticed i was in a forest with lots of snow, some weird fantasy kind of area… have yet to return the favor though, he doesn’t want to know a thing about Lucid dreaming.