I'd like to tell a story. It is not originally mine, but I like the lesson that it teaches.
"It concerns Master Hauchecome, who on market day went to town. He ... noticed a piece of string [lying on the cobblestone]. He picked it up and carefully put it in his pocket. He was seen doing so by his enemy, the harness maker.
"At the same time it was reported to the mayor that a pocketbook containing money had been lost. It was assumed that what Hauchecome had picked up was the pocketbook, and he was accused of taking it. He vehemently denied the charge. A search of his clothing disclosed only the piece of string, but the slander against him had so troubled him that he became obsessed with it. Wherever he went he bothered to tell people about it. He became such a nuisance that they cried out against him. It sickened him.
"His mind kept growing weaker and about the end of December he took to his bed.
"He passed away early in January, and, in the ravings of his [death] agony, he protested his innocence, repeating:
"'A little [piece] of string--a little [piece] of string. See, here it is, [Mister Mayor.]'"
[The "Piece of String," http://www.online-literature.com/Maupassant/270/. Taken from Gordon B. Hinckley, "Slow to Anger," October 2007 General Conference, http://lds.org/general-conference/2007/10/slow-to-anger?lang=eng&query=piece+string]