Sleep...
The best thing to do to recharge our minds and bodies, but for some people, it can be very exhausting too - that feeling you get when you've spent the whole night sleeping but you feel more exhausted than the end of the busy day before. There are a lot of weird things that happens while we sleep and most of the time, we are not even aware of those.
When your mind is awake but your body is paralized. You are still able to breathe normally but you find that it is impossible for you to move any part of your body and you might also not be able to speak. The paralysis later ends naturally when you go back to sleep (and wake up normal) or when someone touches you, it may end as well.
Sleep talking and -walking...
This is something you are not aware of unless someone tells you that you have been walking in your sleep, or talking (either to yourself or another person) while you were asleep. It is usually very embarrassing and makes it stressful for the person doing it.
Exploding head syndrome...
When you wake up from a loud noise in your head which sounded like an explosion or the deafening sound of a gunshot and your head feels fuzzy.
When you suddenly stop breathing while sleeping and have to wake up to get some air. The muscles in you mouth relaxed and causes your tongue to obstruct the breathing passages.
Dreaming the same thing over and over again, OR having the same nightmare over and over again, OR dreaming in a series (episodes).
Falling...
A feeling of falling and not being able to make it stop or a feeling of falling on your bed - especially when you fall asleep and your body suddenly gets a fright (as if your heart stopped) from a this feeling.
A dream within a dream...
When you are dreaming that you are dreaming and wake up but find yourself still in the same place or position. Usually when this happens, you only remember it after a few days.
Resources:
http://www.healthline.com/symptom/stopped-breathing
http://www.sleepeducation.org/sleep-disorders-by-category/parasomnias/exploding-head-syndrome/overview-facts
http://www.sleepeducation.org/sleep-disorders-by-category/parasomnias/sleep-paralysis/overview-facts
http://www.webmd.com/sleep-disorders/guide/sleep-paralysis#1