Perspective

I reckon a bad mood is essentially a loss of perspective.

I was just at the cafe talking to the girl who makes the coffee. She's from New Zealand, and on the tele in the cafe is the news, showing the latest terrible statistic of 75 dead in the earthquake. Her face looks distraught, and it's obvious she just doesn't want to be working today.

Leaving the cafe, my grumps were cured. Perspective regained.