Possibly have you ever endured a common cold? Probably did you get rid of it? Certainly you got over it! You won't cure a cold directly, yet your system typically establishes resistance to any cold infection within several days. That is called treated by your personal immunity!

Adults have currently had a lot of the runny nose infections. Parents have developed immunity to the ones they have suffered from. Therefore there are not so many cold infections existing for grownups to acquire. That is why parents just acquire a few colds annually and kids succumb to 10-12 colds per year.
https://www.openlearning.com/u/sandridge-qmfb0b/blog/NaturalRemediesForHpvAndCervicalDysplasia/