(Image Credit: Matthew Cavanaugh/EPA)

WASHINGTON - As President Obama inaugurates a second term this weekend, no one arguably has a better view, in public and in private, than Valerie Jarrett, his closest friend and White House adviser from Chicago, who calls this moment one of "excitement, pure joy."

Jarrett, 56, who holds an exclusive perch steps from the Oval Office, has been by Obama's side through the highs and lows of his first term, from the passage of Obamacare and the killing of Osama bin Laden, to a series of horrific mass shootings and ugly arguments with Congress over the so-called fiscal cliff.

Now about to embark on a second term, Jarrett told ABC News that she and the president have an advantage from lessons learned on the political journey of the past four years.

"I think we are all more experienced. Isn't that what you say when you get older? It's just experience? A little grayer. We are all a little grayer," she said, laughing heartily during an interview in the West Wing. "The president's gray hair is very funny. Mine, not so much. And we are wiser. We're wiser."

Jarrett said there have been lessons even in those small issues that were hard to settle during the first term.

"On his desk he has a little plaque that says, 'Hard things are hard,'" she said of Obama. "You know what? They are."

As she predicted in an ABC News interview on the eve of the first inaugural, Jarrett said President Obama has found the isolation that comes with life at the White House "very, very" difficult.

"Don't get me wrong. He is so honored and humbled to be the president of the United States," she said. "But he is a very spontaneous person."

One small personal victory, she said, was Obama's refusal to give up his personal BlackBerry, which he still carries with him most days. "He kept that. We were unable to pry that out of his hands," she said with a smile.

But Jarrett says the small group of personal friends who have electronic access to the president know that under federal law, every message becomes a part of the public government archives. "No one writes anything interesting these days," she said.

As for the private oath-taking Sunday, Jan. 20, as mandated by the Constitution, Jarrett says the president chose the Blue Room, with views of the National Mall, because it is his favorite.

"To just look out, it's such a privilege to see the gathering that takes place on the Mall and so many people who come to Washington just for that, because they believe in him and they believe in the presidency," she said.

Jarrett said she plans to stick around well into a second term for what she calls the "bold" agenda Obama has planned for the months ahead.