Everything happens for a reason. Nothing happens by chance or by means of luck. Illness, injury, love, lost moments of true greatness, and sheer stupidity all occur to test the limits of your soul. Without these small tests, whatever they may be, life would be like a smoothly paved, straight, flat road to nowhere. It would be safe and comfortable, but dull and utterly pointless.
Develop a central theme, main idea or thesis that clearly explains the purpose behind your autobiography. For example, your theme might be about how you overcame obstacles to become a stronger person, or it might explain why a particular passion -- such as mountain climbing or rescuing animals -- is so important to you. Back your theme with details and background information about your life experiences. For example, you might explain that your dad is in the military, so you've had to learn how to adapt quickly to new schools and unfamiliar environments. Or, you might discuss what it was like growing up in a poor, single-parent home, but how your family was always willing to take in injured or stray pets.