A story

In a non-descript time-space continuum, there was this girl. And one day, this girl came across her fairy godmother/magic goldfish/lucky leprechaun (it doesn't really matter which one). And the fairy godmother/magic goldfish/lucky leprechaun said to her: 'Little girl, this is your lucky day. I can grant you one wish today, make a wish, any wish!'. So the girl thought about it, and as she was a very kind soul and on that particular day she felt rather generous, she said: 'I wish I could heal people. I wish that just by a simple touch, all illnesses and diseases would be cured instantly. I want to be able to help everybody, and bring happiness into their lives'. So the fairy godmother/magic goldfish/lucky leprechaun granted her wish. The girl became a miracle healer, and soon the word went round, and people from all corners of the world were coming to see the girl, and be healed by her miraculous touch. Mighty kings and sheikhs offered the girl treasures and titles in exchange of her healing hands, but the girl declined, politely, every time, as she was happy as she was, just herself and her gift, as she enjoyed being able to heal people. One day a dark prince tried to kidnap her, so he could keep her in his faraway castle just for himself, but she managed to escape. Soon she had to employ people to guard her.
She was not able to sleep or eat anymore, as people were queueing constantly, day and night, waiting to have their ailments cured by her. She started travelling the world, in order to reach the really poor and ill who could not afford coming to see her in her home. On her journey she changed many lives and brought happiness to millions of people. She could have felt happy, had she not been so exhausted, hungry and bruised all over her body. Because she was touched by so many people, her whole skin became a bleeding wound.
One day she died, from her wounds. Because although she could heal everybody else, she could not use her gift on herself.
Upon her death, the fairy godmother/magic goldfish/lucky leprechaun smiled a thin smile.

What is the moral of this story?