When I was a kid, I remember sitcoms and cartoons always implied that eating ___ (fill in the blank) before bed caused weird dreams for the characters. I haven't heard accounts of this actually happening or even heard it mentioned since my childhood.
I guess, if whatever you ate bothered tyour stomach, it could cause a restless sleep and affect your dreams that way.
Percoset is supposed to be some pretty strong stuff. I've heard enough about it to know that i hope I never have to take it.