This question is asked to see how serious a candidate is about his or her career. Some people might not know their long term goals, and some people might have long term goals of becoming rich and retiring early. Those are incorrect answers for this question. The type of answer you want to give is an ambitious answer that shows you really love your career. A good interviewer will read between the lines and find out if a person is going to be a hard worker or just a mediocre one. Being descriptive and shooting for a big goal is something interviewers want to hear.
Short Answer
"After a successful career,I would love to write a book on office efficiency, I think working smart is important and I have many ideas, So gaining more experience,I'm goinig to try to write a book"
