What's the Reason?

What is the real reason to have a blog? To say you do? To prove to others you can? To impress others with your writing or thinking skills? To prove to yourself that you have purpose? To see how many people will like you and follow you? To be a part of something bigger than you...the world wide web? To show people that you've got a great life that they can only wish they have? To share your life's lessons learned to help others? To contribute to society? All of the above? None of the above? Some of the above? If you have a blog...what IS your purpose? If you don't have a blog, should you? Everyone has a story. Everyone has something to share. Everyone knows something that could help someone out. I think that's my purpose. But I admit, at anytime, i could fall into one of the aforementioned reasons. But hopefully not too often.