I love that aphorism. Unintended consequences. We should teach unintended consequences in grade school, high school, and have advanced degrees in it. How to see them before they explode, how to mediate them, and how to fix them once they're running at full steam.
Lately I've been imagining it along with the slowly boiling frog story and the crab-mentality too. As in some people can't tell we're headed to hell because it's coming so slowly, and some people will actively stop others from escaping hell or trying to fix the situation.