Annoying kids in dramatic movies?

Why oh why, in every dramatic movie, must there be the obnoxious little kid that, in a moment of crisis when everyone is fleeing to safety, suddenly runs back to retrieve a pet or stuffed animal, or otherwise doesn't stay with the grownups like they should, compelling the hero/main protagonist to run back & get them, thus endangering everyone? Examples: "Star Trek Insurrection," where the kid goes back into the cave as it's collapsing. Can you name some others? It's such an annoying plot device!