Being pessimistic can make life less easy and it is also less good for your health. So, it would be better to try to be more optimistic. 

Pessimism (from the Latin word pessimus superlative of malus meaning “bad”) refers to a state of mind in which an individual perceives life negatively. He only sees the bad side of things. Pessimism is thus opposed to optimism, a state of mind characterized by a positive perception of the world. 

There are different types of pessimism. Some people have a defensive pessimism (these are the ones who prefer to think of the worst in order not to be disappointed. Others think that being pessimistic makes it possible to face unhappiness: we speak of pessimism of preparation. Finally, defensive pessimism is a pessimism of superstition: waiting and saying the worst makes it possible not to bring bad luck to happiness. 

The pessimist spoils the good times of life. The pessimistic person does not have the happiness of anticipation and even at the last moment he is only sparingly happy about what is happening. Pessimism also does not prepare for unhappiness. Faced with a misfortune, the pessimistic person will suffer as much as the optimistic person. Finally, pessimism can harm social relationships including family relationships. Living or working with a pessimistic person can be complicated. 

Pessimism can also be harmful to health. Various studies have shown that being pessimistic has a negative impact on health. One study found that pessimistic people treated for cancer had a higher risk of death. Pessimistic thoughts would also lead to a greater risk of having Parkinson’s disease or some form of dementia. 

How do we explain this effect of pessimism on our body? Pessimism would interfere with the efficiency of the endocrine and immune systems. 

Being pessimistic is not a character, so it is possible to change and become more optimistic. Help from a therapist is helpful. Cognitive and behavioral therapies and positive psychology are advised to be successful in becoming more optimistic. 

To try to be less pessimistic, you can draw inspiration from the advice of Christophe André in his book Vivre joie. The psychology of happiness:

• Beware of yourself and cultivate humility. You are not always right, and optimistic people are not necessarily naive.
• express less of your negative thoughts (like “this won’t work”). Your loved ones are so used to hearing you grumble that no one takes what you say into account!
• Check your predictions. If 9 out of 10 times they were wrong, you might be wrong!
• Ask yourself if it is more interesting to be happy or to be right. Being able to say from time to time to optimists “I was right” is a meager benefit compared to happiness.