The originator of the idea of "learned optimism, Martin Seligman, sees the individual's explanation for good and bad events as coming from three different dimensions-- the internal/external, the permanent/temporary and the pervasive/specific.
An optimist generally takes credit for good events (internal), believes that all the good event's positive results will be long-lasting (permanent) and that other aspects of his/her life will be impacted by this good event.(pervasive) When bad events transpire, the optimist tends to see outside circumstances as being responsible(external), doesn't believe the affects of the bad event will last (temporary) and sees them as being limited to this particular event (specific).
Seligman further believes that you base your personal sense of worth on your view of the events that happen in your life. Instead of folding under the defeat perceived by a pessimist, an optimist will often make choices for self-improvement. They are usually positive goal-oriented and persevering in their attitude of deserving of happiness.
Optimists generally expect to succeed and their success reinforces their expectations. It's a win-win vicious cycle. Curious about how optimistic you are? You can get hold of an Attributional Test here.
Harvard Psychology professor, Jerome Kagan, believes that children's temperaments (timid, bold, upbeat, melancholy) position them early on for confidence or a lack, but that intervention can change the outcomes (otherwise, why would you and I be going through this together if it were not possible for us to change into optimists?).
An optimistic person is well set up for success and happiness, with the confidence to handle both negative and positive events in their lives. It's a good thing.