There's actually a scientific term for jingles that get lodged in your head: earworms... A study published earlier this year (the researchers gave subjects the 'Catchy Tunes Questionnaire') found that the worst way to get rid of earworms is to try to get rid of earworms. The more you think about trying to forget them, the deeper they burrow. This is pretty much true about consciously trying to forget anything. There's even a name for the phenomenon: ironic processing. The best advice I've heard for making earworms go away is to just stop being irritated by them, and come to peace with the fact that you're humming Britney Spears.
--by Joshua Foer, memory expert and the author of Moonwalking With Einstein: The Art and Science of Remembering Everything