Small children love opening and shutting closet doors. This, of course, can lead to pinched fingers, especially if you have two of them trying to do it simultaneously.
If you are Martha Stewart, you address this problem by sewing cute little pillows that coordinate with your decor and slipping them over the doorknob to keep the door from shutting fully.
If you're me, you leave some wadded-up clothes hanging halfway out of the closet. It accomplishes the same thing.