"Complaining does not work as a strategy. We all have finite time and energy. Any time we spend whining is unlikely to help us achieve our goals. And it won't make us happier."

-Randy Pausch

"The best way of avenging yourself is not to become like [the wrong-doer]." 

-Marcus Aurelius

Let go of how things ought to be and find joy in where you are.

"When you rise in the morning, give thanks for the light, for your life, for your strength. Give thanks for your food and for the joy of living. If you see no reason to give thanks, the fault lies in yourself." - Tecumseh

"We are what we repeatedly do. Excellence then, is not an act, but a habit." - Will Durant

"Such as are your habitual thoughts, such also will be the character of your mind; for the soul is dyed by the thoughts." - Marcus Aurelius

Keep at it.

“If you are going to achieve excellence in big things, you develop the habit in little matters. Excellence is not an exception, it is a prevailing attitude.” 

-Colin Powell

“There are hunters, and there are victims. By your discipline, cunning, obedience, and alertness, you will decide if you are a hunter or a victim.” 

-James Mattis