3: Hypnic jerks. That sensation that you're falling and have the brief panic is the hypnic jerk. If you have a poor sleep pattern you're mor likely to suffer from this.
4: Exploding head syndrome. When you're falling asleep or waking up, you may have the experience of a bright flash and the sound of an explosion, a bit like someone has thrown a flash bang into your head. The cause is currently unknown.
5: Your body releases arginine vasopressin. Vasopressin is an anti-diuretic hormone the body releases to stop you having to pee all night, and is produced as you fall asleep. The effect of this hormone causes your body to produce less urine. AVP may play a role in sexual motivation and pair bonding.
6: Sexsomnia. It is possible to have sex while you're asleep. People who have sexsomnia may appear to be completely conscious and aware of what is happening, even though they're asleep. It can also occur frequently between couples who fall asleep "spooning".
7: You wake up. This isn't waking up like you do when your alarm goes off, but a brief moment of consciousness as you move between different sleep cycles.
8: A cousin of spiders will have sex on your face. See thread post #1.
9: The brain updates it's database. While you're asleep your brain will shuttle all the data from short term memory to long term memory, and work out which information is important and which it can safely forget and ignore.
10: You will change position 35 times. Even if it's just to get comfortable, you'll change position around 35 times.