The Reason For Lingering Irritability

Irritability can be a hard mood to break out of because it often creates a negative feedback loop that is self-reinforcing in ways that can deepen its hold on our state of mind.

It reinforces our negative mood such that we're much more likely to fixate on anything even mildly upsetting or annoying (we might even do so unconsciously as a way to validate our bad mood).

Focusing on all these annoyances then fuels our irritability further, which in turn, focuses us even more intently on validating our irritable mood by continuing to scan our environment for external frustrations.