How is the moment of realizing a fundamental shift usually characterized?

Answer

The slow, insistent drip of a faulty faucet

The realization that something fundamental has shifted is rarely signaled loudly; rather, it is often compared to the slow, insistent drip of a faulty faucet, where the accumulating effect is finally noticed.

How is the moment of realizing a fundamental shift usually characterized?
advicetransitionlifechangedecision