If you keep humming a song despite thinking about it actively, it could be because of the phenomenon called earworm.
As per Neurosurgeon, Dr. Arvind Bhateja, earworm is a catchy tune or melody that gets stuck in your head and repeats itself over and over again. They can be triggered by listening to a song on your playlist, at a restaurant, or just by thinking about a tune you heard recently.
According to experts, earworms are generally not considered a serious medical condition, but they can be annoying and distracting, especially if they persist for a long time.
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