Of Mice and Men blog:4

Why do dreams fail?

The definition of a dream is a) a series of thoughts, images, and sensations occurring in a person’s mind during sleep; b) a state of mind in which someone is or seems to be unaware of their immediate surroundings; c) a cherished aspiration, ambition or ideal. I think that the best definition would be option b) because it’s not specific to what type of dream it but still says that they are unaware, so they could be asleep or still awake.
There are a couple different ways you could dream, one can dream while asleep, and one can dream while awake, which is called daydreaming. I think that daydreams are more what you actually want and or need because one typically blocks out all the sounds and things going on around them while daydreaming.
Dreams fail because sometimes they aren’t always true, or you can’t remember them. Also because sometimes when you’re sleeping you’re able to hear what other people are saying, and that can get into your dream and make unreal and go a different way from where it was heading, which can be a bad thing, because then you might go into nightmares and other stuff, which is bad.