What Gives You Nightmares?

Things that haunt you and are unpleasant to you are the things that gives nightmares. Something that's very sad to happen, very awkward, or may be something that happened in an instant, something bad and scary.

All these occurrences gives you nightmares.

It can be a few things,
you could of seen something scary.
A lot of the time if you have socks ON when you are asleep you get to hot and uncomfortable.
If something bad or scary has happened to you.
The thing you fear the most
if you just have a "nightmare" about a friend not talking to you say, it could just be if your friend has not talked to you in the past, you will think of it and dream it but differently.