system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't we grow back teeth?
gpt
We as a species didn't have a genetic need for it. Those that do (sharks) end up constantly replacing teeth. 

Remember our brain is vastly larger compared to most other animals and the caloric input to keep it running meant trade offs elsewhere. 

You do realize very few animals have more than one set of teeth anyway. We are lucky we get even two.