There is this toy my cat Mira loves which recently has taken to getting stuck, painfully I imagine, in between her teeth. Each time she plays with it, she does so with such abandon and fresh, happy Attack Cat glee that it's as if it's the very first time she's ever seen this bouncy wire with cardboard tied to the end (no, I did not fashion it myself. It's called "The Cat Dancer," and it has to be the very least sophisticated cat toy ever invented. But oh the wonders it inspires!). And each time, she is similarly surprised (as am I, frankly, although that is a whole other issue) when the wire gets jammed between her teeth and she can't get it out for uncomfortable minute upon uncomfortable minute. Although we play with this thing almost every day, she can never remember that it can end up hurting her if she's not careful. Or else she can't comprehend why The Dancer would hurt her again, when look how much fun it is, bouncing! bouncing! in the air!
Granted, I should probably not give her this toy. But Mira weighs 17 pounds and might drop over dead if she doesn't get exercise, and this is the only toy she has even the most remote interest in. So she and I both keep going on with it, full of blissful denial.