Do people really want the real you? All of it?
The answer will, of course, depend on the audience and the forum.
If you are writing a blog about drug addiction, telling your most horrifying stories is a prerequisite. Your audience will expect it.
If, on the other hand, you are writing a blog to support your tax preparation business, you probably want to keep most of your tales of woe out of it — no matter how “real” they may be.
Being “authentic” means being genuine. It means having an honest conversation with your audience. Within reason.
So how do you know what is too much you, how much is not enough, and where the sweet spot is?