Wouldn't eating stuff dropped on the floor improve your immune system?

I don't go around licking toilet seats but if I drop something on the floor in my house or on my desk I just brush it off. Never gotten sick from it. In fact I rarely get sick at all. Am I retarded or are people seriously over blowing the dangers of germs? You here about how kids eating dirt and stuff boosts their immune system. I don't see why it should be any different for adults.