Sure.. but this also means that you don't have to take public transportation, that you probably don't have small children, and you likely don't work in a school, pharmacy, daycare or hospital.
Bragging about sick days is hardly indicative. Many if not most places in the states don't give sick days, and folks are forced to go in when sick because they can't afford not to.
I should now mention that I worked 8+ years at a pharmacy, and a school before that. I rarely got sick and I didn't do most of your precautions. Just basic hygiene, and got my flu shot every year. And I directly led folks to cough and cold medicines.
Some of this time, I stopped to get coffee most days (there was a mcdonald's next door).
I just get sick even less now, but that's mostly because my lifestyle naturally isolates me (not in a bad way).
I'll also say that sick folks can - and do - get you sick before they show symptoms, and a lot of folks that cough or sneeze do not have any disease that you can catch: Smoking (pot or nicotine) causes coughing: Allergies and irritants cause both coughing and sneezing. You can only do so much.
You've just been lucky and have a lifestyle that allowed you to keep away from people to an extent, though the hand washing does help out and honestly, if anyone picks up one of your habits, it really should be somewhat frequent hand washing.