First off, when I did my personal statement, everyone who saw it thought I should change something. I took some advice and used it, others I ignored. Just remember it's your statement! I would include both. They want you to include why you want to be a Naval Officer as well as what your goal is in STA-21. In mine I harped a lot on that it was my dream to become a Naval Aviator since I was in High School. My advice (take it or leave it) write it as though you will get picked up (ex. "when I am picked up for STA-21", not "if I am picked up for STA-21"), make sure you say why you want to be an officer, and what your goal is in STA-21, also if you have anything negative in your package (bad high school GPA for me) make sure you address it in your statement and how the situation has been corrected. Good luck, and if you have any question you can PM me.