There is a story of a young, but earnest Zen student who approached his teacher, and asked the Master, "If I work very hard and diligently, how long will it take for me to find Zen?" The Master thought about this, then replied, "Ten years." 
The student then said, "But what if I work very, very hard and really apply myself to learn fast -- How long then?" Replied the Master, "Well, twenty years." "But, if I really, really work at it, how long then?" asked the student. "Thirty years," replied the Master. "But, I do not understand," said the disappointed student." At each time that I say I will work harder, you say it will take me longer. Why do you say that?" 
Replied the Master, "When you have one eye on the goal, you only have one eye on the path."

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His boss, Dev Patnaik, founder and chief executive of Jump Associates, and co-author of "Wired to Care: How Companies Prosper When They Create Widespread Empathy", was talking to his team and offered up this observation (paraphrased and somewhat broken telephoned):

With negative thinking, you can achieve Goodness, which is born out of fear and desire to improve. 
True Greatness requires optimism, which stems from the belief that you are deserving of success, love and affection.

If this isn't a case for optimism, I don't know what is.

"Never try to be better than someone else; always learn from others, and never cease trying to be the best you can be because that's under your control.  If you get too engrossed, involved and concerned in regards to things over which you have no control, it will adversely affect the things over which you have control."