I normally don't take any medications for a cold. Truthfully, ever since I started walking a few miles a day outside I very rarely get colds or "minor" illness

I normally don't take any medications for a cold. Truthfully, ever since I started walking a few miles a day outside I very rarely get colds or "minor" illnesses. In the past I would get a cold maybe once every year or 2, and then it would suck for about a week while riding it out. I used to get bad colds too. To the point where when I was kid they wanted to put tubes in my ears to drain liquid out. But the last time I had a cold was ~5 years ago. I remember last year I spent 6 hours sitting directly next to someone on a plane who looked severely ill with cold-like symptoms. Sniffing every 20 seconds, clearing his throat often, looked super pale, major bags under his eyes. Overall looked miserable. I thought I was done for, but somehow managed to not get sick in potentially one of the worst situations possible for getting sick. I don't know what to make of it but I remember my dad telling me that often times the kids of a farmer are the healthiest people around and the moral there is they were constantly around things that might not be considered sanitary so their bodies built up a natural immunity. Basically, mild exposure to non-ideal things helps you out a lot (which includes vaccinations for more serious non-common germs of course).