Your PS needs to be your "shock and awe" portion of your application. Don't ever just say a whole bunch of things (such as each and every reason why you want to be a physician). Show the reader why you want to be a doctor. For instance, in the section of my personal statement where I talked about why I wanted to be a doctor, I told two stories from personal experience (one about when I was working at a refugee camp and one about a 16 year old patient that I worked with that had acute polyneuropathy) and how those experiences helped drive me towards medicine. The best personal statements are stories that will stick with the reader, because at the end of the day, you want them to remember you. Your personal statement should create in them a desire to know you more (which will get you an interview). Your personal statement is the only thing the differentiates you from the pack. Use it well!! In reference to your interview, unless they ask for clarification for something in your personal statement, don't talk about it. They have read it and decided that they want to know you better, you will waste your interview if you tell them things they already know about you. Tell them different stories about why you want to be a physician and why you are a good fit there. Everyone says they are compassionate, hardworking, blah blah blah... Prove it! In short, your PS should make them want to know you better, while your interview should prove how awesome you are.
