Why are some people restless and talk during sleep while others do not?

Question

I'm asking this question because all my life I have been one of those people who cant stay still in bed and constantly talks while asleep. The weird part is that often when I blurt something out it ends up being an insult. Sometimes I would even swear and be mean which is something I rarely do while awake. In some cases I have had conversations with people standing next to me and was rude to him/her. I don't have any memory of most of this happening and the only things I can remember saying are "Come here you little...!!" or "Stupid!" or even "Plastic bag!". My subconscious must be a jerk lol. Also I kinda have accidentally hit and gotten uncomfortably close to the ones I was having to share a bed with at the time.
What do you think might be the cause of this happening?

Actually I dont think I'm such an angry person. However i do keep things to myself so maybe that might have something to do with it.
By the way I'm the complete OPPOSITE of a gregarious personality.

I'm definately not a social butterfly. I've never done sleep walking in my life either. However I'm kinda good at remembering what happens if I wake up or my eyes are open. I'm extremely sensing and sensitive during times such as this. A couple of times I have overheard people talking about me and confronted them when I woke up the next morning. lol it's a little weird I know.

Answer 1

If it started when you were young, it may be a condition that will always be with you to a degree. Meditation, exercise, and a good diet can help. I take it that you don't normally insult people when awake. I don't know if you build up any anger during the day, that you may be venting at night. You don't have to sleep with people, I don't. Some people need to protect their personal space more than others.

Answer 2

Some of us work out our daily stress in our dreams. Are you kind of a high strung and a social butterfly? It tends to happen more with gregarious types. Somnambulism or 'sleep walking' tends to go along with it.

Getting enough rest is important otherwise when you do crash, you go almost immediately into a rem sleep cycle where the verbal outbursts are likely to occur.