Virus invasion volume is the key to surviving COVID-19. If a large enough volume of viruses infect an ordinary healthy body its payload will overwhelm the host and possibly kill. A very small virus invasion would allow the body time to create antigens and destroy the invader.

This is similar to the way a vaccine works. A vaccine gives the body the blueprint of a virus so it can build its defenders but the virus has no ability to replicate (technically it’s attenuated)

This is why otherwise fit, healthy, young frontline medical staff often die from it. Without effective PPE the viral exposure is massive.

It is also why some people are asymptomatic - they had such a low initial infection that the body can easily defeat the virus but also pass it on.

Six feet distancing does not guarantee you won’t catch the virus, it just allows you to lower the likely payload and subsequently survive the infection. Be safe, be lucky!