I had a very serious case of "ear worm" as a teenager, with the phrase "Jersey Guernsey in sombre and illustrious weather" (André Breton), and with the beginning of Pound's translation of "The Seafarer." "May I for my own self song's truth reckon / Journey's jargon..." I could just not get those phrases out of my head. There may have been others but i don't recall what they were. I must have had "sombre and illustrious weather" in my head for at least six months.

I still get phrases stuck in my head like that--along with melodies. I had "Stardust" playing in my head for about a month earlier this year. Sometimes though you want to shake those annoying melodies you also feel a compulsion to listen to them.