POSITIVE ATTITUDE by Charles Swindoll

This may shock you, but

I believe the single most significant decision I can make on a day-to-day basis is my choice of attitude. It is more important than my past, my education, my bankroll, my success, my failures, fame or pain, what other people think or say about me, my circumstances, or my position. Attitude is that "single string" that keeps me going or hinders my progress. It alone fuels my fire or assaults my hope. When my attitudes are right, there's no barrier too high, no valley too deep, no dream too extreme.