I've read about how the subconscious mind can't distinguish fantasy from reality, which is why when you're dreaming something completely ridiculous, it makes perfect sense at the time. I recently had an interesting experience regarding this.
I was having a strange dream Sunday morning. In it, I was having fun at the beach with some people late at night, and I saw an old teacher that I had been fond of (Mr. Rhode, for those who are curious), wearing a grey trenchcoat and waiting to cross the street. He never wears trenchcoats, by the way. Of course, I haven't seen the guy for 10 years, but I didn't really say anything to him. He invites me to go to a job interview, but I say that I already have a pretty good job. After a bit of convincing, I decide to go with him. (I'll skip over the whole part about how I suddenly get a truck as a gift from my mother, but don't like it because it has an automatic transmission rather than a manual, and that causes me to make ridiculous physics-defying mistakes with it. That takes place during the day, but somehow happened in between him talking to me and me driving to the place later that night [but showing up at sunrise the next morning? It wasn't very far...])
I never get to the interview because while I'm in the waiting room, I'm distracted by a very friendly and attractive girl. But apparently she's just part of the plot to lure me into another room, where I get locked in with her and some other people. The "company" (maybe it was a front for some secret government organization) just wanted to do experiments on me, see? But I actually stay voluntarily, because it happens to be fun, and they give me the impression that I can leave at any time. A bunch of ridiculous and humorous stuff happens, and I escape four years later, fighting my way out. I had a beard down to my stomach by that time.
Anyway, they had apparently gotten to everyone I knew and convinced them that I was some kind of terrorist. So wherever I went, my friends/family members were attempting to turn me back in... it was terrible! I had no place to go, and it was pouring rain, and I had only jeans and a t-shirt on. Furthermore, my truck, which I had left parked in the parking lot of the company's building, had rusted thoroughly. So I was at my wits end, and decided to wake/get up.
[Digression here] Dream states are similar to hypnotic states, in which the subconscious mind is susceptible to influence. The subconscious mind constantly goes about influencing a person's perceptions and reactions to bring his/her reality into concert with what it believes. Hypnosis for change [e.g. to stop smoking or whatever] works by convincing the subconscious mind of something that is different from what it currently believes. The subconscious mind is actually quite powerful, far more powerful than people realize. An analogy I'm fond of is that of a little dog being walked. It's tugging on the leash and its master generally lets it go where it wants. The little dog thinks its in control of the situation, but the reality is that the guy holding the leash is, and can forcibly direct the little dog's course at any time. The little dog represents the conscious mind, and the master, the subconscious. The analogy isn't perfect because the master would be "conscious" as well, whereas the subconscious mind is not... quite. But the point is that the subconscious mind is generally content to let the conscious mind have its way, but when conflict arises, the subconscious mind always wins. This is why most attempts to break habits by fighting the subconscious fail (though some people may have success, depending on how much consideration their subconscious gives to their conscious desires). I feel like going into how the subconscious mind is almost like another, separate being, being quite secretive, and having its own desires, knowledge, and abilities, but I'm already too far off topic.
Phew! Anyway, when I looked in the mirror in the bathroom, I actually felt a twinge of an "I'm free!!!" kind of feeling, and when I ate some food, I had a "Wow, real food!!! It's been so long!" kind of feeling, and because of that, I was eating somewhat more voraciously than normal. Weird, eh?