C.S. Lewis once said, "Even in literature and art, no man who bothers about originality will ever be original: whereas if you simply try to tell the truth (without caring twopence how often it has been told before) you will, nine times out of ten, become original without ever having noticed it."
Another man by the name of Solomon, far wiser than Mr. Lewis wrote, "What has been is what will be, and what has been done is what will be done, and there is nothing new under the sun."
That's blogging in a nutshell. It's about writing something original with no hope of saying something that has not been said before, and much better.
So why do it? You'll do it because you have been sitting, half a century it seems, in front of that monitor with something inside of you: A gift. And you're not sure what form the gift will take because so many times the form is so unclear. The gift you have is words. They well up and then subside only to sit uncomfortably just below the surface of your consciousness waiting to be given. You'll do it because you know in your heart that the words that you write are meant for someone. Who it is you don't know, and may never will, but that gift inside of you is meant for someone. And it will change their lives.
And who knows, you might just be original.