Looking at optimism through the lens of Learned Optimism by Martin Seligman 

The world is what we make of it; we act upon how we see it and how we see ourselves.  However, running an executive search firm, just like any other entrepreneur I often deal with set-backs and have come to realize that there are two different ways entrepreneurs can look at hurdles; here is how Learned Optimism explains it:

In the book Seligman discusses the two ways that we can look at our set-backs.  First, there is the pessimist that whenever something bad happens to him, he thinks the worst is going to happen.  Seligman defines a pessimist as someone who sees bad events as permanent, will undermine everything that they do in life and are their own fault.

While some bit of pessimism is okay, people who think this way are more prone to depression, has long bouts of listlessness, tend to have bad health and do not live as long.

On the other hand, the optimists believe that bad events are just a temporary setback.  They believe that defeat is not their fault, rather it is a bit of bad luck.  When confronted by a bad situation, optimists tend to look at the hurdle as a challenge and try harder.

What is the difference?  Seligman goes on to explain that the ways of thinking have two consequences.  Hundreds of studies show that pessimists give up more easily and get depressed more often.  On the other hand, they show that optimists do much better in school and in college, at the office and in sports.

In the book, Seligman goes on to explain how optimistic behavior can be learned and that we are not helpless over bad events in our life.  While it takes practice, thinking in a positive manner pays off.