Earworms are songs that crawl into your head and stay. 98% of us have had a song stuck in our heads. Six of the worst offenders are "It's a Small World," "The Lion Sleeps Tonight," "Don't Worry; Be Happy," "Macarena," "Gilligan's Island" theme, and "Y.M.C.A."

For those who didn't catch that, I repeat: the songs most likely to stay with you the longest are "It's a Small World," "The Lion Sleeps Tonight," "Don't Worry; Be Happy," "Macarena," "Gilligan's Island" theme, and "Y.M.C.A."

Once again, those songs are "It's a Small World," "The Lion Sleeps Tonight," "Don't Worry; Be Happy," "Macarena," "Gilligan's Island" theme, and "Y.M.C.A."

It's not known why songs like "It's a Small World," "The Lion Sleeps Tonight," "Don't Worry; Be Happy," "Macarena," "Gilligan's Island" theme, and "Y.M.C.A." stick with people but it isn't unusual for songs like "It's a Small World," "The Lion Sleeps Tonight," "Don't Worry; Be Happy," "Macarena," "Gilligan's Island" theme, and "Y.M.C.A." to do just that.