Writing demands the most awful, amazing combination of overwhelming egotism and overwhelming humility.
If you start thinking you have something to share, you lose the humility. You're preaching to the reader. You're saying I know this, and this is important, and you sit there while I tell you about it. And you can't lose that humility.
On the other hand, if you don't assume you have anything to share, and you write anyway, just for the sake of what you may discover, and the hell with the reader, you're working from a point of view of total egotism, and you can't lose that either.