An experience in the past

It was six o'clock in the afternoon when I arrived at my house with the tight face, just see me my mother asked me that I passed. I quickly told him that I had fought with one of my friends. She saw me so distressed when she told him the story, which told me to sit down a moment to his side. My mother told me a story as she told her my grandmother, said thus: two friends travelled through the desert and at a particular point in the journey discussed. The other victim, with nothing to say, wrote in the sand: today, my best friend I beating a slap in the face. Continued on and arrived at an oasis where decided to bathe. He had been slapped and hurt started drowning, being saved by the friend. Recover it took a styled and wrote on a stone: today my best friend saved my life. Intrigued, the friend asked: why after that I hurt you, you wrote in the sand and now you write on a stone?  Smiling, the other friend replied: when a great friend offends us, we must write in the sand where the wind of forgetfulness and forgiveness will take care of deleting it and shut down; on the other hand when you pass something great, we record it on the stone of the memory of the heart where no wind throughout the world you can delete it. When tell me my mother this cartoon so curious I was so blown away that I spend all the anger.