Yes, it is in the dictionary; defined as being unreasonably or illogically optimistic. And, again yes, there are times when excessive optimism can be annoying and even inappropriate. When someone has suffered a serious loss of a limb or a loved one, a comment that is extremely optimistic may be hurtful.
Books helped me survive a difficult childhood, especially when I was bedridden for many months without access to television. It was at that time I was given a copy of the classic book by Eleanor H. Porter. At a time when I felt ”hopeless,” the story of Pollyanna was a great inspiration. Although I certainly never succeeded in following in her footsteps, her glad game did motivate me to become optimistic rather than pessimistic. For those who are not familiar with her character trait, just before Pollyanna’s dad died, he taught her the glad game. He believed that no matter what happens, there is always something to be glad about. (Years later, I learned how this notion is similar to those scriptures in the Bible where we are taught to praise God in every situation).
Although some consider a “Pollyanna” attitude to be unrealistic and foolish, many times adopting an attitude to see the good in most situations contributes to a much happier life than one who is determined to focus on the downside of things and assumes a more negative attitude.
One thing I know for sure: whenever I have intentionally decided to look for the good in every situation, my life has been far more enjoyable than times when I allow myself to become hopelessly pessimistic. Pollyanna gave me hope for a better life when I was a sick child and that hope has never abandoned me.