Yes I have had a cavity and have had it filled
Well then there is that possibility they don’t know they have a cavity especially if they don’t go to a dentist. Unless you go to see a dentist on a regular basis you won’t know that you have one until it gets worse at that point you start feeling pain that is what happened to me, and I don’t wish that kind of pain on nobody not even my worst enemy.
I am amazed by several people that have never had one!