It is true that we should always motivate ourselves in order to get going in this world. But being optimistic or pessimistic seldom make us forget of what our true ability is and indirectly we cheat ourselves. For me, life is just life and we should live it to the fullest. Don't be like all those motivator who keep us to believe on something we know that is not going to happen. They only tell us things that we want to hear and that thing is always a lie. They a just another hypocrite. Be a realist not a optimist nor pessimist.