Why pessimism is a bad idea.

"First, you are likely to get depressed easily. Second, you are probably achieving less at work than your talents warrant. Third, your physical health--and your immune function--are probably not what they should be, and this may get even worse as you get older. Finally, life is not as pleasurable as it should be. Pessimistic explanatory style is a misery." (Seligman's Learned Optimism, p. 53)

Basics of optimism

From Seligman's Learned Optimism

Basically, the optimist is different than the pessimist in three vectors:

1. pervasiveness - optimists view problems as not indicative of the entire situation, but local. i.e. a friend criticizing you is not indicative of his entire attitude toward you, but an individual critique.
2. permanence - pessimists think that problems are here to stay, while as optimism knows that problems, like everything else, are transient.
3. personal - optimists recognize their proper influence on events, and don't assume that all bad things happening to them are their fault. pessimists tend to blame themselves.

positive emotions

Positive emotion can be about the past, the present, or the future.

The positive emotions about the future include:
optimism
hope
faith
trust.

Those about the present include:
joy
ecstasy
calm
zest
enthusiasm
pleasure
flow

The positive emotions about the past include:
satisfaction
contentment
fulfillment
pride
serenity

(via Seligman)