In addition to being annoying, being told to be happy all the time actually backfires. As a society, we have become increasingly intolerant of negative feelings. This "feel-goodism" perpetuates the myth that bad feelings are unacceptable, should be treated with a pill or at the very least controlled and silenced.
Research shows that a bad mood per se is not the problem. What matters is your attitude toward the bad mood.
In other words having positive attitude toward a bad mood makes a difference.
Related research highlights the benefits of a good cry. In a study, those who believed welling up with tears is a good way to relieve emotions felt better later on after watching and weeping through a sad movie.
If you are in a funk or particularly bad mood, "What can I learn from it?" Channel your inner Sherlock Holmes and do some detective to figure out what triggered it. Is there something else going on that you need to address? Most importantly, don't beat yourself up for being in a bad mood. The truth is occasional bad moods can be part of a good life.
It turns out bad moods can have a bright side.