"Deep sleep"?

Question

WHY IS IT ALWAYS WHEN WE ARE HAVING A DREAM WE ARE INTERRUPTED BY SOMEONE OR SOMETHING, AND WHEN WE FALL BACK TO SLEEP OR ROLL OVER WE CAN'T PUSH-UP WHERE WE LEFT FROM?

Answer 1

That is the sub conscience you are talking about.  Once we come out of subconsciousness, you can go back in.  Of course, if you have the ability to lucid dreaming, that may have a chance.

Answer 2

You wont remember your dream unless you wake up with in 20 min of having it.  Thats why you always wake up in the middle of a dream.

Answer 3

it's because you have like 1239273489 dreams in one night, and you only remember them if you wake up in the middle. and actually, if you are really tired, you can start where you left off.

Answer 4

when you go to sleep the information you got from that day is being transferred to your permanent memory and when two or more memories bump into each other they cause a dream that lasts two to three minutes.