i dont understand rappers

on the way home from the chemist and a song comes on the radio...taking it back, 19th century style. what the? i think. and then it begins

who's that?
who's that?
who's that rappin at my chamber door?
it's mr
mr raven
all up in my grill like never more

all. up. in. my. grill. like. nevermore.

what the hell does that mean?

and arent rappers supposed to be all individual and whatever, yet their songs are full of similies. is that what they're called, when your compare something to another?

examples from this fantastic song:
Cell phone mute like Paris Hilton
Times a changing like Bob Dylan
killing me softly like the Fugees
joy inverse just like Fred Durst
Afflicted calm, like Michael Moore

it then ends with 'who's house? ravens house'

i hope never to hear that song again

why was i at the chemist, you ask? well, as you will already know i am quite partial to chemists. i like them for things. you know, things? and stuff, they're good for stuff too. like newsagents and the australia post shop, all good for stuff. anyway, why was i there? cos the cats gave me ringworm. 'but its ok,' said the chemist lady, 'its a horrible name for something that isnt realy that bad. its actually a fungal infection which sounds so much nicer'

yes, that does sound nicer, almost pleasant