Well, in their family, they had a good-night verse that went like this. Maybe not an obsession but definitely a healthy interest!

Gute Nacht (good night)

Scheiss ins Bett dass es kracht (shit into the bed so that it bangs)

Reck den Arsch zum Mund (stretch your ass towards your mouth)

und sei recht kugelrund (and be spherically round))

And Mozart wrote a canon from it

"Buona Nox - bist a rechter Ox" (and the end of the text is what I wrote above)