“I’m glad to be in Philadelphia,” Benjamin Netanyahu said when addressing a graduating class at the University of Pennsylvania in 1999. “A pretty good portion of my intellectual capital was developed in this city.”

Few are aware that Israel’s prime minister — due to address Congress in a historic joint session today — spent four years in the City of Brotherly Love as a teenager. Netanyahu’s father Benzion moved from Israel to Cheltenham, Pa., in 1963 to teach at Dropsie College, America’s first center for post-doctoral Jewish studies, now the Katz Center for Advanced Judaic Studies at the University of Pennsylvania. With Benzion came his children, including Yonathan and his younger brother “Bibi,” the future prime minister.

And, just like “The Addams Family,” these fish out water had to go to school: Cheltenham High School in Cheltenham, then a Jewish enclave in suburban Montgomery country. The school had no shortage of Jews, but the Netanyahus’ intellectual capital was out-of-step. These teenagers came from a desert where their people were fighting for survival to a world of high school plays and sock hops not far removed from “American Graffiti.”

It was a world they questioned.

“My school has about 1,500 students who don’t know what they’re doing there,” brother Yonathan — later killed fighting for the Israel Defense Forces during their celebrated 1976 hostage-rescue mission at Uganda’s Entebbe Airport — wrote in a letter home to Israel in 1963. “It looks more like the Tel-Aviv Sheraton than a school (beautiful even by American standards, brand new, and it cost 6.5 million dollars to build). My house is ‘terribly’ nice, surrounded by lawns and trees and empty, meaningless life.”

While the prime minister has left few sound bites about his high school years, some who knew Netanyahu said he was not interested in the Summer of Love.

“He was completely counter-counterculture,” Deborah Lefco told The Washington Post in a telephone interview in 2010. Lefco graduated from high school with Netanyahu in 1967.

“It was the Vietnam era and we were all against the war in Vietnam because we were kids,” she said. “He was the lone voice in the wilderness in support of the conservative line in those days.”

One article about Netanyahu’s life as an American high school student even compared the contrarian to a certain rebel without a cause.

“He kept his hair short at a time when most boys wore their hair in a big swoop over their eyes,” the New York Jewish Week wrote in 1996. “He was cool in his own way, proud to love his parents when that was unfashionable; friendly, yet intense, like James Dean, never smiling in photographs, but comfortable with strangers.”

Though occasionally portrayed as the class grump, Netanyahu made a go of it. He joined the chess club. He played, ahem, left wing on the soccer team and, as one former teammate told the Jewish Exponent in 1996, showed “anger when he wasn’t playing well or the team wasn’t playing well.”

But he may have felt like he was from another planet. While there was enthusiasm for Israel in Cheltenham, before — or even after — the young country’s Six-Day War with Egypt, Jordan and Syria in 1967, the stakes were perhaps not apparent to the average debutante.

“There was no question that he thought most of the kids in our school were living superficially,” said Thomas Stretton in a 2010 interview with The Post. Stretton had the curious experience of teaching Arthur Miller to a boy who would become a right-wing Israeli ideologue.

“I think we were talking about ‘Death of a Salesman,’ ” Stretton said. “He made the point that he thought there was more to life than adolescent issues. … He saw the world differently from the suburban, fairly prosperous population that made up the school at the time.”

Even shul offered no escape. Perhaps because of a family connection, the Netanyahus ended up worshiping at Temple Judea, a reform synagogue in North Philadelphia.

“It was a reform congregation with very liberal leanings,” said Harvey Porter, the synagogue’s former president, in 2010. “The interior was like a Quaker meeting house.”

Perhaps not eager to remain a member of a congregation likened to a Christian pacifist sect, Netanyahu left Cheltenham to join the Israeli Defense Forces shortly after graduating high school.

According to one account — from Cheltenham High’s former yearbook editor — Netanyahu didn’t even bother showing up for his diploma.

“I’d see Benjamin everyday in class,” Zelda Rae Stern told the New York Jewish Week. “He was my friend. And then one day in 1967, he just wasn’t there anymore. No messages, nothing. … And then I started reading about troop movements in Sinai.”

Though he returned to the United States to study at the Massachusetts Institute of Technology in the 1970s, he was just visiting. America had welcomed him — but his family wasn’t interested in staying.

I keep aloof,” Yonathan wrote. “And I do so not because I dislike them, but because I feel I belong to a different world.”

Speaking at the American Israel Public Affairs Committee's annual policy conference on Monday, Israeli Prime Minister Benjamin Netanyahu said he did not intend upcoming address to Congress to be divisive or disrespectful to President Obama. (AP)