clipped from clicks.robertgenn.com

You may have noticed the odd times when something is irking you, putting you into a bad mood, and you sit down at your easel and do good work. While it's not as pleasant as when you're in a good mood and everything is coming up peonies, it works to your benefit in another way. In my experience, a bad mood helps the attention span and the critical faculties--not necessarily to be more creative--but with a wider vision and a sharper focus.

Professor Joseph Forgas at the University of New South Wales in Australia has now produced research that shows people in a negative mood are more critical and more attentive than regular happy folks.

Sadness, he found, actually promotes information-processing strategies best suited to dealing with demanding situations. Other bad-mood benefits the professor found included less gullibility, improved assessment of others, and memory improvement.

No human life is all joy, none is all pain. It may be necessary to have a bit of one to gain more of the other.