Cockney rhyming slang for “knackered,” if you’re “cream crackered” then you’re incredibly tired.

A “knacker” was the person that slaughtered worn-out horses in the 19th and 20th centuries for their meat, hoofs, and hide. So, if you’re “ready for the knacker’s yard,” you’re exhausted beyond relief.

“This week’s done me in already, and it’s only Tuesday. I’m cream crackered.”