President Obama could have answered the question as George W Bush did by saying that he couldn't think of one mistake he had made as president. "Can't think of anything" he said. Someone in the audience should have refreshed his memory by reminding him about the unnecessary war in Iraq, which cost over a trillion dollars and hundred of thousand of lives; the unpaid for Bush tax cuts; the unpaid for medicare prescription drug coverage; the squandering of the surplus he inherited from Bill Clinton.