Ash that's funny. So it seems you're very susceptible to ear worms, you only need a bit of a song to have to stuck in your head. Is it actually with the music, or only the lyrics?
I know the effect, but it's rare for me. And then it's more the music, not the lyrics. But I pay more attention, or feel more of the music and less of the lyrics of songs anyways.
I'm with you actually in being more of a melody than lyric person. It can definitely be the music too. If my wife is flicking through her instagram on her phone looking for cat videos and I hear a melody line that reminds me of a song that I'm more familiar with, it will ear worm it's way in. Although, thinking about it, I do value lyrics a lot, but more when I'm actively listening to music... meaning I stop everything else and want to just enjoy an album or something.
That's another interesting topic on its own... the balance between favoring the music or lyrics/meaning of songs.
