Optimism represents a spontaneous flow of love; optimism also represents trust in love. This shows that it is love, trusting love which is optimism. Pessimism comes from disappointment, from a bad impression which is there of some hindrance in the past. Optimism gives a hopeful attitude in life, whereas by pessimism one sees darkness on one's path. No doubt sometimes pessimism shows conscientiousness and cleverness, and pessimism also shows experience.