This old(ish) Overcoming Bias post by Anna Salamon and Steve Rayhawk is one of the best things I've recently read.
Though perhaps I was oblivious of something that should have been clear to me. Please let me know how obvious the post's argument was to you.
HT Julian.
One unsolicited criticism: I think the post is too long, and that you can stop reading just before the paragraph that begins with "(2)".