Optimism and pessimism may be well understood by the case as follows; two persons thirsty

to death run for a small glass of water with only ten percent water left. One person was overjoyed and said "there is still a little water in glass", while the other one sighed and murmured "little water left". The first one can be described as "optimistic" and the other one "pessimistic". Keeping an optimistic attitude has been more important nowadays. Can you explain the reasons？ Write a composition of about 200 words on the following topic; Why Is Keeping Optimistic So Important？