Why Did You Leave Your Last Job? 

This depends on several factors. Different Individuals have different answers for it.
You can answer as - " I will most likely be involved in a different but still related career path; something to do with the creative side. If I were to start over I would attempt to get myself to specialize in one area as a young man. It’s very interesting to follow one’s interests all at the same time, but you don’t get anywhere very quickly this way. By pursuing lots of interests all at the same time, it takes a long, long time to acquire professional level skills."

The best way to respond to the interview question "What are your goals for the future?"

Don't discuss your goals for returning to school or having a family, they are not relevant and could knock you out of contention for the job. Rather, you want to connect your answer to the job you are applying for. Examples of good responses include:

=> My long-term goals involve growing with a company where I can continue to learn, take on additional responsibilities, and contribute as much of value as I can.

=> I see myself as a top performing employee in a well-established organization, like this one. I plan on enhancing my skills and continuing my involvement in (related) professional associations.

=> Once I gain additional experience, I would like to move on from a technical position to management.

=> In the XYZ Corporation, what is a typical career path for someone with my skills and experiences?

Sometimes it's best to talk about short-term and intermediate goals rather than locking yourself into the distant future. For example, "My immediate goal is to get a job in a growth-oriented company. My long-term goal will depend on where the company goes. I hope to eventually grow into a position of responsibility."

Why are they asking?

The interviewer wants to find out the following:

  -How committed are you to the career and the company
  -How much do you understand about the career path ahead of you
  -How passionate are you

Approach 
Research the job and the organization structure and relate your career plan and progression with the job posting and progression of the company.

Eg.
I would like to work hard and grow with the company to a respectable position with additional challenges and responsibilities and contributing to success of the company.

Please don't give these answers...
"Doing your Job"
"Working somewhere else"
"No idea"
"I haven’t thought that far ahead"
"Have a family"