I have another perspective that is gained from having served on the Admissions committee at the University of Arizona College of Medicine. 1.Personal statements should be interesting and informative. Your really do not have a choice. You must be proactive about advocating why you want to enter postgraduate training. The reader will want to know that you understand what you're getting into.
Relevant experiences are therefore important to relate.
In my experience, too many young people are reluctant to tell their story. They think that they are bragging or being arrogant. Remember, if you do not tell your own story, no one else will. You cannot assume that those who will write about you will capture what you yourself want others to know about you. Most students who are bound for postgraduate programs do not need to be motivated.