One of the questions my graduate school has asked me to answer is: Describe a major change you have experienced at work and how you handled it. I am only 23 years old and have been in school all my life. I have never experienced a change of any kind at work. How do I answer a question like this?
Even though you think you have never faced a life-altering change in the workplace, you actually have had such an experience. You have made the transition from high school to college and, if you are applying to graduate school, we know that you made the change successfully. In order to answer this question properly, just talk about the personal and professional characteristics you have that made it possible for you to make this transition.
Talk about maturing, both as a person and as a student. You could add something about self-discipline and learning to develop goals, both short- and long-term. No high school student magically becomes qualified to attend graduate school. That takes years of hard work and perspective. During those years, your life completely changed every semester and you had to adjust to it. Some of those adjustments were easy and some were not. You had to stay focused on the overall goal, while continuing to live your life in 4 ½ month blocks of time.
That takes a great deal of self-discipline and maturity, both qualities you will need (in abundance) in graduate school and in your chosen profession. Remember, the school is looking for mature students in graduate programs, not someone who is unable to adjust to change and will end up wasting their time and your money.