I wouldn't overestimate your immunity to the flu. It is most likely because many of your fellow Americans got a flu shot and you are protected by herd immunity. But stopping this thing is not about you, it is about getting the economy up and running again. You can open up things as much as you want but as long as people stay home, stop, making purchases due to uncertainty, supply chains shutting down, etc. If getting a shot and wearing a mask helps in any way, then I see it as my duty as an American to help out any way I can.