A small Biden moment, a cool Obama reaction

No joke: Barack Obama had to take the presidential oath twice. No, seriously, Joe, no joke.

One of the small but memorable moments to emerge from Obama's first full day in office on Wednesday came when Vice President Joe Biden offered up a quip that did not seem to thrill his new boss. Those who have followed the vice president's long career as a senator chalked it up to Biden being Biden.

The scene happened when Obama asked Biden to swear in some senior staff members of the new administration.

"Am I doing this again?" Biden said. He was apparently referring to the fact that he had already sworn in members of Obama's Cabinet earlier in the day, including some people who were in the room in front of him at the Eisenhower Executive Office Building.

"For the senior staff," Obama clarified. "For the senior staff, all right," Biden responded.

And then Biden said this: "My memory is not as good as Justice Roberts, Chief Justice Roberts." The line drew an "oooh" from the audience, the kind one gets after serving up a zinger.

Chief Justice John Roberts, as millions of people saw on Tuesday, had slightly flubbed Obama's original oath, which prompted Obama to do the same.

Obama did not laugh or even smile at Biden's line. His look and body language were serious. Cable news outlets replayed the moment prominently.

Biden is known for sometimes getting himself in trouble with his words - or as critics would say, shooting from the lip. Obama knows this, saying Biden has a penchant for "rhetorical flourishes."

What most people didn't know then was that Obama, in fact, was going to have a rare do-over of the oath Wednesday night.

Roberts came by the White House to deliver the oath to Obama again - flawlessly - out of what the White House called an abundance of caution.

Apparently there's a time and a place for jokes, because Obama offered one himself.

He told reporters in the Map Room for the brief ceremony that he and Roberts were going through the drill again because the first time was "so much fun."

The do-overs only went so far. Obama did not re-sign the executive orders he issued on Wednesday before taking the oath a second time.

White House press secretary Robert Gibbs said that step was not necessary because the White House counsel's office still considers that Obama "was sworn in appropriately and effectively" the first time.