You know, when you ask yourself, "What's my purpose in life?", or especially when somebody asks you what you think about your purpose in life, and more especially in this particular situation, it is a good time to look at the many possible perspectives...
Mom, dad, "What's my purpose in life?" No, wait... I'm old enough, mature enough, to ask myself...
"What did my parents teach me about my purpose in life?"
"What did my family teach me about my purpose in life?"
"What did my sports coach(es) and team mates teach me about my purpose in life?"
"What did Scouting teach me about my purpose in life?"
"What did the OA teach me about my purpose in life?"
"What did my church/synagouge/temple teach me about my purpose in life?"
Ahh...
"What has God taught me about my purpose in life?"
Hmm...
Now, ask yourself again, "What's my purpose in life?"
As noted in previous posts, one page is fine, two max. Keep it simple; keep it real. Don't answer all the questions I just posed; but, make it yours... Tell them what's important to you. And make your ambitions lofty because you'll never get to Mars if you don't believe.