this song is about a guy who cant get a girl out of his head no matter what he does to forget her she is stuck in his head and he cant do anything about it.

ain't no doubt about it
i can't live without it
tried to forget you
but i can't get you outta my head
just when i think you're gone
you come back and turn it on
and just like a simple song
i can't get you outta my head

this song uses imagery because i can picture a guy doing many differet thing just to forget the girl but nothing that he does is working.