Danny, 10, can recite the Five Pillars of Islam: faith, prayer, charity, fasting and pilgrimage.
Jeremy, 12, understands the difference between Predator armed drones and Global Hawk surveillance drones; between 500-pound "dumb" gravity bombs and 2,000-pound "smart" precision-guided bombs.
Gabe, 14, knows that Pastun and Dari are the spoken languages of Afghanistan while Pastuns, Uzbeks and Tajiks make up the main ethnic groups.
Zack, 18, can locate most of the "stans" -- Afghanistan, Pakistan, Tajikistan, Kyrgyzstan, Kazakhstan, Uzbekistan and Turkmenistan.
Since Sept. 11, on a practical and comprehensible level, my sons have learned about the religion of Islam, the military capability of the United States, the ethnicity of Afghanistan and the geography of Central Asia.
On an impractical and incomprehensible level, they have learned that their world can change horrifically and irreversibly in a split second.
They have learned that evil exists.
"Your lives will never be the same," I told them on Sept. 11. Even more than Dec. 7, 1941, altered the lives of their grandparents and Nov. 22, 1963, altered the lives of my husband, Larry, and myself.
Some changes happened immediately. I put a halt to Zack's early decision application to an East Coast school. I forbid visits to theme parks, stadiums and venues with large gatherings. And I replenished and expanded the emergency supplies.
In the following few weeks, in a warranted and comforting burst of patriotism, we adorned our car windows, garage and boys' bedroom walls with American flags. My younger sons replaced pop singers and athletes with firefighters and police officers as their heroes. And we mourned the victims, crying as we read their encapsulated biographies in The New York Times "Portraits of Grief."
Six months later, our lives are still not the same.
Yes, the fear of immediate danger is less palpable.
Larry and I have let Zack apply to three East Coast colleges. We have allowed Jeremy to visit Magic Mountain and Gabe to visit CityWalk and Century City. We have resumed going out to dinner, though less frequently, and supporting our faltering economy, though less enthusiastically. We have taken down all the flags except for a child-made felt flag that hangs in the front hall.
But I still nervously await the next terrorist attack on United States territory.
I still cry easily, this last time when journalist Daniel Pearl was first kidnapped and then viciously murdered.
And I find myself agreeing with Dr. Chris Giannou, head surgeon of the International Red Cross, who has spent 20 years in war-ravaged countries, including six weeks in Afghanistan last fall. He said, "For me, the world is divided between the bad and the worst, not the good and the bad."
But my sons, at least outwardly, are more optimistic.
"It's not as if I walk into Dad's office [on the 40th floor] and think, 'Oh no, an airplane's going to fly into the building.' You can't worry about that stuff," Gabe says.
"I can't think about the terrorists all the time. It's too sad. It's what Osama wants us to do," Jeremy adds.
Perhaps their youth affords them more resiliency. Or affords them no basis for comparison, unlike their grandparents who witnessed World War II, or Larry and me who lived through the assassinations and upheavals of the late '60s and '70s. Or perhaps they're repressing fear is too painful to surface.
I see their anxiety, however, when they talk about Israel, when they read about yet another suicide bomber in this increasingly volatile and seemingly insolvable conflict.
"It seems so unfair," Zack says, "that I get to plan for college while my Israeli friends have to go into the army."
These friends include our beloved "adopted" son, Ya'ir Cohen, who lived with us two years ago for three months and visited last October, as well as the other Israeli teens from Tichon Chadash High School who participated in Milken Community High School's Israel Exchange Program.
They also include Gabe's friends from the A.D. Gordon school in Tel Aviv, who visited Heschel Day School last year as part of The Jewish Federation's Tel Aviv-Los Angeles Partnership 2000.
My sons' concerns are heightened by having experienced Sept. 11. By knowing how it feels to have their own country unexpectedly and brutally attacked.
But despite the world situation, which he reads about in detail in the newspapers, Danny is enthusiastically making plans for his birthday party in April.
Jeremy, as Cantor Jay Frailich of University Synagogue says, "is really cooking" as he learns his prayers and aliyot for his bar mitzvah in June.
Gabe is engrossed in rehearsing his lines for Milken's spring production of "Comedy of Errors," in which he's playing Dromio of Syracuse.
And Zack is enmeshed in the final semester of his senior year.
Yes, their lives will never be the same. They have permanently lost their naiveté and sense of invincibility. But perhaps, despite the sadness and the uncertainty, I could benefit from their forward-looking attitudes.
As Robert Frost said, "In three words I can sum up everything I've learned about life: It goes on."