I'm kind of a dream expert, so here's some info on dreams that might interest you.
Children have primitive nightmares - usually about death, these stem from evolution.
It is not known truly what dreams are for, most scientists believe they are for sorting through your brain's memories and keeping important information, that's why many dreams we have are based on events that have happened to us.
It is believed nightmares prepare us for bad things, the ones about death in particular. Being killed by wolves in a dream, for example, stems from an evolutionary trait of preparing yourself for being killed by wolves.
Also, research and testing has shown that dreaming about actions you do in real life makes you better at that action when you wake up. For example, dreaming about playing a video game will make you better at the video game when you wake up.
Also, it is possible with exercises to make yourself completely conscious during dreams, this is called "lucid dreaming". The first step of lucid dreaming is simply to remember dreams. After that, you must try and be aware you're in a dream when you're in a dream. There are many different stages of consciousness in a dream, from simply remembering them to controlling exactly what happens in them. It takes a while but with practice it is possible. While awake, you must create tests to let your mind know you truly are awake, such as counting your fingers or pinching yourself. When in a dream you must remember this and do the same tests in your dream. I'm currently at the stage of knowing I'm in a dream, it's very hard to get further but I'm getting there.
According to lucid dreamers, when completely controlling a dream you can change anything and the dream goes by in "real time" - although it's not real time, your mind thinks it is. Things like lying completely still when you wake-up will send memories of the dream flooding back.
Yeah, just ask if you want more info' on any of that.