Often, particularly with songs that I ‘wake up with’, I can identify a specific relevant line or phrase that is responsible for it sticking in my head. Once I identify that ‘message’ it usually fades fairly rapidly. The relevance of the phrase is not always immediately obvious - it can an associated memory, a simmering concern, or (rarely) a phrase or other song that a passage in the song reminds you of.
Not all ‘ear worms’ fit this pattern, but I find a surprising number do. I consider it related to “meaningful” dreams. (Not all dreams are meaningful. My experience may be caused by my extended experiments with coherent dreams and dream diaries as a child)
Byyyy Mennen! If this didn’t stick in your head for a while, you probably weren’t old enough to remember. Melodies are (in the case of advertising) designed to be retainable to the point of nauseating. Think of your local car dealership or mass home realtor, I bet they have a “catchy” jingle associated with them.
Jingles are designed to stick in your head whether they’re good or hated. Either way they make the product name stick in your head. “I’m lovin it” is a perfect example…that is stupid, but it stays with you. Simple melodies are the key, easily remembered, conducive to marketing, and “lowest common denomenator” material.
A “real” what makes it catchy answer is not really definable.
Could songs and their hooks remain inside ones head for the simple reason that they cannot place it? As in, its an evolutionary advantage for some reason. That enters another realm I cannot begin to understand, but I will throw around a possibility…
It expands the wiring in your brain… Like, it is memorization practice. To be able to subconsciously know a hook but not being able to place the lyrics allows the brain to rigorously use an algorithem or something to systematicly try to remember the words. I would attempt to prove why memory is important, but I will leave that as anecdotal evidence. Thus, people who create radio jingles initially do not include the end of songs because your brain will not have the sense of completion it needs to forget it. Could this also be why one mentioned that if you make your own ending, you forget it easier?
(If my theory above doesnt suffice to logic, well i just made it up…)