How cool would it be if our teeth kept growing back our entire life?

We'd need to chew on rough things to keep our teeth even and free of hooks, ramps and blades -
as do horses and many other herbivores.
If the grass or hand-feeds are too soft, these animals need to see a dentist every year, otherwise the inner linings of their cheeks get lacerated and infected.

That would make it so hard to eat if the grew back un not up or down like they grow when we first get them ...:( 

It would be fine I guess.  I'm thinking of things that do grow back when we lose them....hair, skin, nails, and the one that grows back at fast speeds and can come back bigger, fat.  ;)