That's how it goes with kids. You hardly notice how fast they're growing up.
On the inaugural platform again four years later, a more mature Malia (14) and Sasha (11) Obama smiled, sometimes giggled, and chatted with their cousin Avery Robinson as they awaited their father's arrival.
Sasha bounced on her feet a bit as if chilly; later at the parade she danced in her seat to the beat of passing drummers. Malia, rivalling her mother's 5ft 11in, looked poised in calf-high black boots. Like any girls their age, they whipped out their smartphones to take photos.
Both daughters appeared relaxed and oblivious to their global TV audience, unfazed by the fuss over their father. Meanwhile, fashion-watchers were tweeting about the girls' coats in vibrant shades of purple.
Such attention to the Obamas' clothes, their Hawaiian holiday, their hair -- Michelle lit up Twitter by adding bangs -- will continue as they charge into the teen years.
In the second term, Sasha moves on to high school. She expressed her pre-teen spirit on Sunday, when Barack Obama took his official, non-public oath of office. After giving Dad a "Good job!" she added a reminder of his flubbed words four years ago. "You didn't mess up."
For Malia, the milestones to come are many -- she'll be hitting the years when typical teens start driving, dating and applying to colleges.
How normally can any of this go at 1600 Pennsylvania Avenue?
Life in the White House is bound to feel different to a teen than to a second-grader.
Seven-year-old Emanuel Coleman's grandmother positioned him on the steps of the National Gallery of Art to watch the swearing-in on a giant outdoor screen Monday.
The North Carolina boy thought life for a White House kid must be cool, because the president has "his own private limo, helicopter and lives in a really big house".
Sixteen-year-old Colleen Casey isn't so sure.
"They have to live their life in their dad's shadow," said Casey, part of a group of Girl Scout volunteers who came to the inaugural from Virginia. "You can't be your own person."
That's the struggle for White House youngsters, said author Doug Wead, who has interviewed 19 sons and daughters of former presidents and wrote about them in All The Presidents' Children.
"When your mom's the first lady, and all your classmates are oohing and ahhing over her, it's hard to compete with that," Wead said. "At any given time, half the country hates your father and half loves him. It's hard to establish a separate identity."
Just last week, the National Rifle Association referred to the Obama daughters in an ad berating their father for opposing a proposal to put armed guards in all schools, while his children get Secret Service protection.
Mrs Obama says she strives to give the girls a normal life -- homecoming dances, playing basketball, slumber parties -- and also to keep them respectful, responsible and down-to-earth.
Some feminists want to see the Harvard Law School graduate take on a more forceful public role. Not all her fans are so sure.
"I like the roles she's taken on with troops, with health, with children," said W. Faye Butts (68), who travelled from Georgia for the inauguration. No need to try to do more: "She has a family to raise, that's her first priority."