By chance have you heretofore been down with a cold virus? Peradventure did you eliminate the infection? Naturally you did! You won't cure an acute rhinitis itself, nevertheless your system typically develops immunity to a certain cold virus within a few days. That is called cured by your very own immune system!
Adults have previously had a lot of the runny nose viruses. Parents have actually created resistance to the ones they have suffered from. So there are not so many runny nose infections remaining for parents to acquire. That is why parents only succumb to a couple of colds annually and children may get 10-12 runny noses per year.