put (someone or something) out of (one's) head
To make an effort to forget or stop thinking about someone or something. You need to put that idea right out of your head—it will only bring us trouble. It's been three years since we broke up, but I still can't seem to put her out of my head. Worrying about how your interview went won't do you any good—try to put it out of your head for now.
put something out of your ˈhead
stop thinking about or wanting something: I am not going to let you go to the party, so you can put that idea out of your head.