I'm pretty sure all children have obsessive personalities. They pick one movie that fits their style and become so passionate about it they'll watch it eight-thousand times until they know every single line and their mothers are singing "You've got a friend in me" while washing dishes.
I can't say I'm exempt from this rule either. The Wizard of Oz was a Little-Lo-lo fave back in the day. Maybe we find comfort in hearing the same lines over and over and over.
That must be why kids are disobedient: they like hearing their mothers say the same thing over and over and over and over.......