My personal opinion is that this stuff doesn't really belong in a personal statement. I think a lot of people make the mistake of basically using their personal statement as a paragraph form of a CV or resume. Its not. I also don't think its an autobiography.
A good personal statement is a narrative, has one solid theme, and says something about your personality/history. You don't have to explain every activity you do. I think the best thing you can do is use some type of an anecdotal story/situation to explain who you are/why you are doing what you are. Yeah, you want to throw in positive things about yourself, but it is always better to show someone something than to tell them it. Think about it as if you are writing an essay that gives someone an idea of who you are-maybe for a creative nonfiction writing class.
One tip I've heard is that when you read your PS go through each line and highlight the sentences that could have been true to say 50% or more of the premeds you met.
Example: "Growing up, I experienced how physicians were respected society/helped me etc and thought "Wow, I want to be like that." Something like this could be said by almost anyone that has ever seen a physician. Avoid things that could be said by anyone. "I enjoy teaching, helping people, blah blah." Boring.