A dog held a juicy bone in his jaws as he crossed a bridge over a brook. When he looked down into the water he saw another dog below with what appeared to be a bigger juicier bone. He jumped into the brook to snatch the bigger bone, letting go his own bone, He quickly learned of course that the bigger bone was just a reflection, and so he ended up with nothing.
Be content with what you have, greed and envy seldom pay.