I recently spent the day with a colleague who was symptomatic (unbeknownst to me at the time) and tested positive later that same evening. I was driving around in the same car as her, drinking coffee together, hugged her goodbye, etc. There's no way to draw any meaningful conclusions but I was sure I'd test positive, too. Four tests later and I'm still absolutely fine.
I may well have caught it ages ago and never known, meaning I now have natural antibodies. Or it may be that wearing a mask actually did prevent me catching it. No way of knowing unless I do an antibody test, and I can't really be assed.