The Frog in the Boiling Pot of Water

This is a metaphor that is widely known, and it's the idea of a frog in boiling water. If you add one grain of sand at a time to your existing grain of sand d it still is not a heap. The point being that, ye, things change very slowly over time. There are complexity to those changes,. It's hard for the human mind to be able notice as those changes are happening. And we don't see the situation for just how dire it is. We don't take the action that we should.