I used to be personally very pessimistic when I've been suicidal, but now not anymore. Life is too beautiful and precious to be wasted. Mindfulness is just to remind yourself that your goal in life is to be happy and enjoy it fully and wholly, which I'm doing currently at the moment. Don't worry about the future or the past, just live this present moment fully and wholly, that's it, that's all. How about you? Are you more pessimistic or optimistic in life personally?