Sometimes it hurts my tongue
Altoids are something that I've been using for quite sometime now. I tend to keep a tin of the mints in my car, and they're good as an after-meal breath freshener.
A few months ago when we were down at a Trader Joe's in the US, I picked up this Altoid's gum. It's a cinnamon flavour similiar to the candy hearts that you get around Valentine's Day, except in gum form. It's quite good, and since when I have gum in my pocket I tend to chew it all day, I was getting quite a bit of use from it.
Where the trouble came is that the very strong cinnamon flavour ended up making my tongue all raw, seemingly wearing through a few layers of skin. I put the gum aside, hoping that my tongue would heal, but after about half a week it's still raw and I think I've killed off a good number of my tastebuds.