Keep knockin'
Nobody's home, I'm sleepwalkin'
I'm just relaying what the voice in my head is saying
Don't shoot the messenger, I'm just friends with the...

from Eminem (Ft. Rihanna) – The Monster Lyrics on Rap Genius


The ‘keep knocking’ line refers directly to ‘nobody’s home’ however may also relate to the tics of OCD, many sufferers compulsively knock.

This also has to do with the fact that Eminem constantly puts the blame on his Slim Shady side for his controversial lyrics, as referenced repeatedly on “Evil Twin”.

There’s darkness closing in, there it goes again
It controls my pen, but that ain’t me, it’s my evil twin
But he’s just a friend, who pops up now and again
So don’t blame me, just blame him, it’s my evil twin

Em also mentioned in the 2010 60 Minutes interview that he constantly thinks about rap, to the point where it drives him crazy.

To help improve the meaning of these lyrics, visit “The Monster” by Eminem (Ft. Rihanna) Lyrics and leave a comment on the lyrics box