How long after falling asleep do you start to dream

I fell asleep during some presentation, and when they woke me up I screamed'get your d*ck out of my face!'
But I only was asleep for like 5 minutes
So do you start to dream as soon as you fall asleep?

I guess so... thats kinda funny... lmao lol

did you yell that out loud??? lol
that must have been embarressing...

thats totally funny
I guess you answered your own question

yeah I yelled it out loud!
I was thinking about my ex
then I fell asleep

actually I just learned about this the other day in my class im taking. you sleep in kind of a wave motion when you first fall asleep you could dream but if you sleep for hours and hours you wont know the first dreams in a nights sleep you could dream several times. dreams run through our heads very fast. if it was a movie it would be a very very blurry image. a dream that you think was 15 minutes probably lasted about 1. I got more if you want to know more.

haaha! thats hilarious!

...hahahahaha...wait your ex boyfriend's di*k was in your face? lol :P

ok this might not be a proven fact but I heard that a dream only lasts the very last second of you being asleep but in your mind it portrays like a first or 3rd person movie and could seemingly be an hour long, while really it's only a second.
I don't know though.