What goes wrong when you ignore that default behaviors run when no other instruction is active?

The most common reason fails: Confusing defaults with habits. If a behavior has a clear cue — the alarm rings, you enter the kitchen, you sit at your desk — it is a habit, not a default. Defaults are what happen in the absence of cues, in the gaps between structured behaviors. Treating a cued habit as a default leads you to apply the wrong modification strategy: you try to redesign a vacuum when what you actually need is to adjust a trigger-response pair.

The fix: Set three random alarms on your phone for tomorrow, spaced across your day during times you expect to be unstructured (evening, weekend afternoon, waiting periods). When each alarm fires, immediately write down exactly what you were doing at that moment. Do not edit or rationalize — capture the raw behavior. After all three alarms have fired, look at the pattern. What you were doing in those moments is your current default. Write one sentence describing your default behavior as if it were a program: "When no instruction is active, my system runs [behavior]."

The underlying principle is straightforward: Your defaults determine what you do in the absence of deliberate choice.