Copyright law is vague on this one. As noted above, titles and *short phrases* are not subject to copyright. If someone cares, and has deep enough pockets, they can challenge in court whether what you have used is a "short phrase" or not. In this case, it appears to be a whole sentence, which *is* subject to copyright. That's the legal reality. Now the real-world reality- It is damned unlikely that anybody cares enough to spend a ton of money going after you for the millions you don't have. If you hit #1 on the billboard, I think you might have a problem, and you really might lose in court. My guess is that the likelihood of your song going viral, you getting a new artist Grammy, and ASCAP/BMI and the Harry Fox agency going after you for copyright violation is about as good as the survival of a snowball in a blast furnace in Death Valley. Don't worry- Be Happy. (I stole that line- come and get me.)