If you read an author's works, do you know the author? I present the yeahs and nays.
He who writes can write whatever he desires. He has time to make up things about himself...and to leave other things out. You may read his blog daily, but find out later that his life was full of many things that you did not know about.
A writer who feels more comfortable with paper than people may reveal his true self through his writing. People may be with him every day and yet not know who he truly is. It's the readers who know his deepest thoughts. The masses who read his books may know his heart better than his daily acquaintances.
Draw your own conclusions, but I think that a reader does know the author when she reads his books...particularly if the author is good at what he does.