The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
“My grandmother had six kids - one died as an infant - and she was dirt-poor, and all her kids got an education. And my mom grew up poor. And they both worked so hard and cultivated so much of their own happiness. I wanted to have that like an amulet. Not like armor, but like a magic feather. Like Du”