Of course "head up my ass" (but without the quotation marks) will get a zillion results. Even "Help! I've got my head up my own ass!" without the quotation marks gets a buncha results. But "Help! I've got my head up my own ass!" with quotation marks, meaning I'm looking for that exact phrase, gets zero. By the way, "Help! I've fallen and I can't get up!" (with quotation marks) gets 1760 results.