Cowards shrink from challenges, weaklings flee from them, and warriors wink at them.

Your heart will challenge you, but also reward you beyond your wildest dreams.

Optimists anticipate problems, welcome them, and challenge them. Thus, eventually they defeat their problems.

Discovering and fulfilling your personal destiny is life’s ultimate challenge and its greatest reward.

[Your] dream will challenge, prod and haunt you until you surrender to its call.

Every day you say something or do something that challenges me, changes me.

Excellence does not come from believing in excellence, but from constant change, challenge, and improvement.

One of the greatest challenge in life is not having an attitude but knowing or accepting that you have one

The earth is always changing...readjusting to our existence. Each era is full of unique challenges

“It is the central challenge that the N.F.L. is facing: how to retain those core values as it moves forward,”