Optimism and gratitude have also been linked to people living longer lives, and having a healthier mentality. Optimism has been shown to activate areas of the brain involved in mood regulation. Another interesting fact is that people who work the hardest, tend to live the longest, and pursuing your dreams is what counts, more than achieving them. So in other words being actively engaged in life, and being positive and grateful, is the key to good mental health and a long life.