And of course you will eventually cave in to one more cold, because there remain 300 different runny nose infections. However you will certainly never ever get the exact same cold infection that you had before because you have developed resistance to that particular virus.

Parents have already had a lot of the cold viruses. Grownups have created immunity to the viruses they have suffered from. Therefore there are not as many runny nose viruses existing for adults to acquire. That is why grownups just acquire a few colds each year whereas children may get 10-12 runny noses per year.
http://dantebmos121.tearosediner.net/how-to-kill-hpv-virus-naturally