It shouldn't be distressing. Anyone who enjoys language enough to know it's rules should enjoy it enough to realise that it is a dynamic being. Phonology especially is always changing from one generation to another. With English becoming a sort of lingua franca in the world, phonological changes are only going to become more frequent.
You can't stop phonological change. No more than any other aspect of language. All you can do is keep what you say yourself as you say it.
- For Teachers