Change is the law of life.  And those who look only to the past or present are certain to miss the future.                   John F Kennedy
 
Happiness is like a butterfly;  the more you chase it, the more it will elude you, but if you turn your attention to other things, it will come and sit softly on your shoulder.      Henry David Thoreau
 
The pessimist complains about the wind, the optimist expects it to change, the realist adjusts the sails.                 William Arthur Ward