Kerry tells of boyhood East Berlin jaunt as he enters State Department

John Kerry, the new U.S. Secretary of State, greets employees of the State Department in Washington February 4, 2013. Today is Kerry's first official day at the State Department.

WASHINGTON (Reuters) - U.S. Secretary of State John Kerry spoke on Monday of biking around East Berlin as a 12-year-old, getting a glimpse of life behind the Iron Curtain as well as a grounding from his father, an American diplomat.

Holding up the diplomatic passport he got as a boy when his father was sent to West Berlin in 1954, Kerry, 69, made self-deprecating jokes about how much he had to learn as he greeted employees on his first working day as secretary of state.

"As a 12-year-old kid, I really did notice the starkness, the desolation," he told hundreds of foreign and civil service workers who thronged the State Department lobby where they bid farewell to his predecessor, Hillary Clinton, on Friday.

"If the tabloids today knew I had done that, I can see the headlines that say, 'Kerry's Early Communist Connections.'

"But I would reassure them by saying I really noticed a difference between East and West. There were very few people. They were dressed in dark clothing. They, kind of, held their heads down. ... There was no joy in those streets," Kerry said.

"When I came back, I felt this remarkable sense of relief and a great lesson about the virtue of freedom and the virtue of the principles - the ideals - that we live by," he added. "I was enthralled."

"Now, when my dad learned what I had done, he was not enthralled," Kerry said, prompting laughter.

"And I got a tongue lashing. I was told I could have been an international incident. He could have lost his job," he added. "And my passport, this very passport, was promptly yanked. And I was summarily grounded."

FIRST MALE SECRETARY OF STATE SINCE 2005

Kerry, who was formally sworn in as the 68th secretary of State on Friday, became the top U.S. diplomat after five terms in the U.S. Senate, where he served on the foreign relations committee for some 28 years, the last four as its chairman.

Earlier in his career Kerry worked as a prosecutor and served in the U.S. Navy during the Vietnam War, returning to the United States to testify before the Senate Foreign Relations Committee about his disillusionment with the war.

In following Clinton and her predecessor, Condoleezza Rice, Kerry will be the first man to lead the State Department since Colin Powell stepped down in 2005.

"So here's the big question ... after the last eight years, can a man actually run the State Department?," he said.

Despite his extensive foreign policy background, Kerry joked that he had a lot to learn and would need plenty of help as he took over at the State Department.

"If I'm wandering around the building later and I, sort of, wind up in your office, it's not because I'm there for a meeting. It's because I'm lost and I need directions," he said, again prompting laughter.

"So just tell me who you are. Tell me what you do. And tell me where I am."

Kerry offered no hints as to his policy direction, though he pledged to do his utmost to protect U.S. diplomats following the deaths of U.S. Ambassador to Libya Chris Stevens and three other American officials in the September 11, 2012, attack on a U.S. diplomatic mission in Benghazi, Libya. (Editing by Mohammad Zargham)