system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some people get so many cavities?

I'm not really familiar with the makeup of the teeth, and this is largely anecdotal, but why do some people get tons of cavities? In my case, I was never taught any real dental health by my parents. I probably brushed my teeth once or twice a month (I know, looking back it's absolutely disgusting), max all the way into my late teens when health classes taught me to be more vigilant with dental health. Even then I brushed maybe 3 times a week. I drank sodas and had tons of carbs and sugars as a kid, and went to a dentist for the first time at 26. He said I had no cavities at all. This stands in stark contrast with a number of my friends who would get a cavity filled once or twice a year during their teens even though they brushed 2-3 times per day. Is there a difference in makeup of some people's teeth that causes them to be more susceptible? Are teeth like other bones where your diet as a child can influence how strong they are?
gpt
There's a strong genetic component to oral health.  Some people just have different saliva pH levels and different amounts of carbohydrates and proteins in their saliva, and it all just fosters bacteria growth.  You happen to be lucky in that your mouth mostly takes care of itself.