In conceptualizing a theme, you have to consider the main question, "What would you like to say with your essay?" For example, do you want the admissions committee to understand your choice of major and career in relation to your family background, or do you want to share your passion for your chosen field and your desire to achieve excellence in it? Whichever theme you come up with, this has to be unique to you as an applicant and should be related to your personal background, choice of major, and choice of career. The more unique a theme is, the more interesting the essay will be. In this sense, you can capitalize on personal facts you believe are noteworthy of exposition.
2. Not Enough Focus On the Person _ When one studies the questions actually posed in the residency application requirement statements of most institutions, it doesn't take long to realize that the primary overall aim of the questions is to get to know the applicant better, both as a person, and as a medical professional. This is not surprising when you really think about it. After all, these institutions know that every applicant is a qualified recent graduate of medical school. So, rather than reading about your medical qualifications, which are already covered in your cv, they are even more interested in what you bring to the table as a person and a medical professional. Failing to focus on your personal qualities that set you apart from other applicants is another serious oversight.