Don't be fooled by this trick question. The interviewer isn't interested that you got a new kitten and your parents are in town visiting. The interviewer wants to know why you chose this line of work, your education and how your past employment directly supports the position you are applying to. Answer this question with your rehearsed and memorized elevator speech.
"I knew I wanted to be an ABA Therapist the first time my child needed to see one. I saw the impact she made and the improvements my child made and knew that I wanted to be there for my child as well as other children."
Now is the time to really let your passion show. Think back to the time that you decided you wanted to work with children with Autism. Did you choose this career because you were disappointed in the system? Do you have a family member that you wanted to help? Keep your answer honest and positive. We all know there is a lot of dysfunction in the world but during your interview is not the time to focus on that.