To "get ready for bed" is preparing to be knocked into a deep slumber by a complete stranger you just met at a bar after you've had "one too many"
(you)- "Hey, Tell your girl to meet me in the bathroom in 5 minutes"
(Selvester Stallone)- "Your drunk man... maybe you should go home..."
(you)- "But I'm tired of your mom..."
(S.S.)- "OK PAL! GET READY FOR BED!" (knocks you unconscience)