Bush says his "first recollection" of the CIA tapes being destroyed came when he was briefed recently.
You're intended to think "Golly, he sure is dumb- he says 'recollection' when he means 'knowledge'". Most reporters and analysts will report this press conference as though Bush had said his first knowledge of the tapes came when he was briefed recently.
But Bush isn't lying to you. He was involved in the decision to destroy the tapes and informed when that had been done. Then he forgot all about it. This is a big one with slimeballs like Bush. They're always forgetting this and that, but all this forgetting works in one direction only- to make them richer and you poorer. So his first recollection came when he was briefed recently.
Of course, it takes a village to make an idiot, and he couldn't get away with this without the help of a friendly media that completely ignores the fact that he has just admitted full complicity in the tape destruction decision. They laugh at his verbal skills, but who's laughing last here?