Agreed, but I'll try and make a case for oral diseases being a bit of the same. You get your first permanent tooth quite early. Worst case it came out weak. Or ones parents weren't on the lookout for it and it didn't get brushed. Your parents think highly of you so they let you deal with the brushing at the age of 8. Works for some, fails for many. You were allowed to drink sugary drinks as a kid. Good luck, those are permanent teeth that are supposed to last you a lifetime and they can't handle that.
Some need medication with sugar in it, like asthma medication, and if nobody points it out you can brush like a pro and still be in the risk zone. If your moth is very dry you get them way easier than the rest of us. If you suffer from anxiety or angst you might have a harder time.
You or your parents are just too busy or you are feeling down? Well, 3 months and one of those small cavities might turn into something that needs drilling. You just don't care? Go on vacation to get an implant because bad oral health doesn't equal being unhealthy for a good portion of people.
And that's in our times. After the I think 70s or something people upped their game with fluoride and brushing techniques. The generation before would rarely get to adulthood without something done to their teeth, the generation after some of them forget that there is a reason that they don't have cavities left and right, and don't pass it on to their kids until something is on it's way. Either way it's all new.
All I'm saying is, something happened, your fault or your circumstances whatever, but fixed it in order to carry on.