When I was contemplating surgery on my hip, the thought of taking three (or more!) months to recover had to be balanced with the hope of being able to run, dance, and even sleep without pain. I had learned to live with, and to some degree tune out, the nagging ache, but I was not sure how I could handle limiting myself and my activities for so long.
My image of my self includes physical activity and fitness, as well as knowledge and skills that allow me to teach dance. All of those things would have to be put on hold. I am also highly independent, and surgery required me to stay with my parents for a week and continue to be dependent on friends for rides and assistance for several weeks.
Your self-image can play a major role in your decision making, particularly when it comes to the habits that define your life. Even if it was only going to be a few months, I had to see myself and my life without the usual activity and independence. Other changes you may be considering can require a new, more permanent concept of yourself. When contemplating life change, it can be helpful to evaluate how the change will fit with your personal values, goals, and self-image. This evaluation should include not just a cognitive image and assessment, but also how you will feel about yourself and your life after making this change. 
How do you feel about being “that girl” that carries her nalgene bottle of water rather than drinking soda at the cookouts or football parties? Could you be “that guy” that orders tea at a bar? Are you comfortable being “that guy” that orders a salad with the dressing on the side? Would you like yourself as “that girl” that gets up early every morning to run? How would your life be different if you are “that guy” that is not taking a smoke break with everyone else? I want to be “that girl” who is healthy, fit, active, and tries new things.