I'm medically vulnerable and I ended up getting it because a family member brought it home and I was very surprisingly asymptomic despite having a lot of health issues including mast cell disease destroying my gastrointestinal tract (have feeding tube, underweight and had b12, vitamin d, iron and zinc deficiencies at the time) and neutropenia. Because my gut is in such dire state if I had been sympatomic the immune activation could've cause a major gastrointestinal collapse leading to hospitalisation and being hooked up to TPN. It was totally strange because my mum got floored.

It seems to me that many people who think they've avoided covid probably have just been asymptomatic.