"True friendship is like sound health; the value of it is seldom  known until it be lost." 

"A real friend is one who walks in when the rest of the world walks out."

"Everyone hears what you say. Friends listen to what you say. Best friends listen to what you don't say." 

"A friend is someone who knows the song in your heart and can sing it back  to you when you have forgotten the words."

Anger:

Anybody can become angry - that is easy; but to be angry with the right person, and to the right degree, and at the right time, and for the right purpose, and in the right way - that is not within everybody's power and is not easy.

Your reactions to your enemy can hurt you more than your enemy can.