something is missing here. Who hasn’t had a cold? Do they mean someone who recently had a cold? I usually have 1 or 2 colds a year, and with me they are rough. Since wearing a mask and sanitizers .. zero colds
Not all cold viruses are coronaviruses. So you could have gotten 2 or 3 colds in 2019, and it could be that none of them were the “right kind” of cold to give you this protection.