Hogwash. I won't wear a mask because my immune system needs to receive outside influences in order to work properly. I don't get sick. Don't want to be given 'health advice' from a bunch of Big Pharma Quacks, either. It's a waste of time and effort. Now, when South Korea relaxes their efforts, they'll most likely look like Italy, or even worse.
As you've been told,
the main purpose of a mask is to protect others, not yourself. (this is different in hospital corona wards, where the protective equipment is needed to protect the health care workers). Simple things like wearing a mask and keeping 2 meters away from people are what will allow you to get back to normal, or at least closer to normal.
People in Asia have been wearing masks for many years. Anybody with a cold wears a mask, as a courtesy (look up the word) to the people around them.
I am wearing a mask as I write. I am in my office for the first time in 2 months. Here (Israel) we are getting things back to normal. Slowly, carefully- but we are doing it.
This has nothing to do with big pharma, just common sense. And sorry- South Korea will never look like Italy. Because they won't relax their efforts. And people there care about the society around them. Spain and the UK already look like Italy. The US has a good chance of ending up the same, partly because too many Americans think like you.