Matthews reinvents history again

Media Matters catches Chris Matthews making up ridiculous stories after the fact about the election - one of his favorite tactics. See the Daily Howler for more on how Matthews completely changed his story on the Gore/Bush debates in his book to conform to the dominant media narrative. Why do pundits feel such a compulsion to tell apocryphal stories that rationalize the outcome of elections? (See: George H.W. Bush looking at his watch during a debate, Michael Dukakis's answer to Bernard Shaw's question about the rape and murder of his wife, etc.)