“Scientists call songs that get stuck in your head ‘earworms’ after the German Ohrwurm. We don’t know a lot about how or why they happen — it’s hard to get funding to study this type of thing — but we know a little. Like, it tends not to be a whole song that gets stuck in your head, just 15-20 seconds of one, and it tends to be a simple song that even non-singers can hum without effort.”