you cannot finish because you do not have the life experience.
i expect there are other stories that also should not be finished.
having said that, i will add that a story i once set aside later won a writing contest. it had changed a great deal in the mean time, and i had come to understand a theme the story could illustrate.
so, my advice would be to consider carefully whether a story is worth finishing.
what i do think, is that you, the writer, should keep writing. finish what you are doing, or write something entirely different. just keep writing. 