Interesting, isn't it, how people like hearing the same song over and over?
The same doesn't hold true for lots of other things. People don't like hearing the same joke over and over... the same story... the same lecture. Most people watch a movie one time, maybe two or three times if they really, really like it, but if you tried to get them to watch it several times a week, they'd consider it torture. You don't want to have the same conversation again and again. You might read a really good book more than once, but 40 or 50 times? No way. Yet, I could probably list 100 songs I've listened to at least 50 times each, and still enjoy them.
What is it about certain songs?