This is a dangerous (and common) misconception about the immune system.

I mean its not like I dont touch anything. Its just that the workflow for mcdonalds is touch touchscreen -> pick up food that you hold with your hands -> consume said food with potential bacteria now on the food. This wouldn't be the case for sit down fork and knife dining.

I totally agree with exposing immune system...but at the same time, I guess I am weak enough that there is still downtime in the aftermath when I go out into the city(especially during seasonal transitions and when visiting busy packed rooms).

You don't have to have the other extreme of touching every dirty spot especially in a org like mcdonalds which is more likely than not to have people who dont respect basic hygiene. At the same time you dont need the extreme of not touching anything. There is a middle ground.