At first, Obama didn’t think his performance was a complete disaster. But he began Thursday morning by watching excerpts of his own performance and was especially struck by his own tentative, grim demeanor — especially when he and a more relaxed Mitt Romney were broadcast in split-screen. It was worse than he thought, according to one person close to the situation. He was subdued but positive on a conference call with staff. …

His mood was radically different Thursday — not just calm but buoyant, loose, focused. It reminded several aides close to the president of his response to Hillary Clinton’s stunning comeback win in the New Hampshire primary in 2008. It’s a cliché in his camp that Obama only feels really motivated when his own destruction is in sight, but the magnitude of his lousy performance clearly motivated him as he plunged back into campaigning. …

With Obama, it’s not just about will — it’s always about mood, too. For all that’s been written about his flop in front of roughly 67 million viewers, the reality, according to the people who know him best, is that he just wasn’t in the right headspace. The president had too many conflicting thoughts bouncing around his head and could never quite reconcile his desire to attack Romney with his fear of alienating voters by appearing angry or unpresidential. The result was a muddle that has given Romney new life.