I think that some adult toothpastes may have other things that aren't really good for kids, like if the toothpaste is whitening, or something. There do seem to be toddler toothpastes (meant for under-2s who swallow), kid toothpastes that are sweet flavors like bubblegum, and then kid toothpastes that are less sweet and more minty, but possibly milder than adult toothpastes? It's interesting how many varieties there are. When I was a kid, I remember having a sweet toothpaste and thinking it was so delightful, I'd try eating a bit. Well, it might seem sweet and delicious when you use it to brush your teeth, but it's icky when you actually eat it. I never tried that one again! And yes, I guess like others I naturally wanted the fresh minty flavor after a while and changed to preferring that.