Indeed, I'm not sure even testing is sufficient. My family recently got it (my wife and I visiting my parents), but thought nothing of it for a week. My father had a sore throat, my mother had watery eyes and some nasal congestion. My father masked indoors (because I don't want a regular cold either) and chalked my mother's symptoms to seasonal allergies (the cars were covered with Pine pollen all week). Then, on the drive home, my wife felt off. 10 hours in the car together. She slept in the guest room that night and, just for grins, tested for Covid the next morning. She was positive. We called and had my parent's test - both positive. I tested negative so I packed my things and rented a hotel room for the week and worked there alone. I tested every other day and was never positive, but I cancelled all my client meetings.

I still never "got it" but...is it really feasible I didn't have some low level? This is my second trip in a car for multiple hours with someone who tested positive the next day. Granted, I'm about 4 vaccines in (2xOG, 1 updated, 1 XBB variant), but so is my wife. I have to think that I had some sub-clinical level of viral load, or at least below the antigen test threshold, but I'm thankful I escaped symptoms.