A little while ago, I chipped a tooth. Let's just say I've learned that when I'm trying to eat something which turns out to be harder than I thought, I no longer think that I can still crush it with my mighty super-hero teeth.
And now I need to go to the dreaded dentist. Or so the logical part of my brain likes to tell me. Then there's the not-so-logical part, which likes to point out that the worst thing that can happen, is that it dies and falls out. And you can't even see it unless I do this:
There aren't really a lot of situations where that facial expression is called for.