Billy's Got a Rock

Billy carried around with him a particular rock his whole life.  When Billy was a boy his dad gave him this rock.  His dad told him it was very valuable and he should always keep it close.  Billy looked at this rock everyday and thought about what the value really was...$10,000?   Or $20,000...or was it worth a million dollars?  One day he lost the rock throwing him into a panic attack followed by a month of depression.  But, fortunately the rock was found and given back whereupon Billy resumed his daily ritual of looking at the rock and fantasizing about its worth.  Some time later he really needed money for medical expenses, he was diagnosed with cancer and was dying.  He went to the jeweler to appraise the value of the rock.  The appraiser laughed in his face, the rock was worthless.  Billy had been lied to.  He had his hope in something that would never deliver or satisfy.  He was left with nothing.