To "be prepared" means to be ready for what may happen, not just what is expected. It means planning ahead, having the right tools or information, and staying calm under stress.
Whoever strives for good must be prepared to endure evil. John of Damascus
To be prepared for war is one of the most effectual means of preserving peace. George Washington
A community is like a ship; everyone ought to be prepared to take the helm. Henrik Ibsen
To be prepared is to have no anxiety. Korean Proverb
If you choose to make friendship with a pig you must be prepared to live in the mad. African Proverb
If you want to smear somebody's face with mud, be prepared to dirty your hands. African Proverb