Can anyone help me to find the title of this song ?

its a rap/ hip hop song and i heard it at forever 21 , it goes

" but chu aint gotta act like you know "

i think that's how it goes , but thats all i know and i can't find the title .

wild guess.. try Timbaland (ft. Jay Z & Justin Timberlake) - Laff At Em
http://www.youtube.com/watch?v=xUkM85LYbFQ
they have a line like this in the chorus
I've never been to Forever 21, but maybe they play this song..

It's a hip hop/rap song and i heard it at forever 21 , it goes ...

" but you aint gotta act like you know "

i think that's how it goes, and i think it was a remix but i'm not sure .

Try "Ral Mafia" by Yukmouth

Yours aint a lot act like you know