Likely have you once been down with a cold virus? Conceivably did you recover from the problem? Naturally you survived it! You can't heal a runny nose itself, yet your body typically develops immunity to a specific cold infection within a couple of days. That is called treated by your very own immune system!

Adults have in the past had a great deal of the runny nose viruses. Grownups have actually established immunity to the ones they have had. Therefore there are not quite as many runny nose infections around for parents to become infected with. That is why grownups only succumb to a few colds each year and children get 10-12 runny noses annually.
https://www.storeboard.com/blogs/general/hpv-can-it-be-cured/4422007