Winners keep track of results. Losers keep track of reasons. George Sheehan

Shallow men believe in luck, believe in circumstances -- it was somebody's name, or he happened to be there at the time, or it was so then, and another day would have been otherwise. Strong men believe in cause and effect.
- Ralph Waldo Emerson

Hold yourself responsible for a higher standard than anybody else expects of you. Never excuse yourself. Never pity yourself. Be a hard master to yourself - and be lenient to everybody else.
-Henry Ward Beecher