It was one of the more emotional moments of President Obama's farewell address. His eyes swelling with tears, he spoke of his wife, "Michelle LaVaughn Robinson of the South Side," and then, of his pride in their two daughters, Malia and Sasha.
"Under the strangest of circumstances you have become two amazing young women," Obama said. " You are smart and you are beautiful. But more importantly, you are kind and you are thoughtful and you are full of passion."
"And," he added, pausing for applause, "you wore the burden of years in the spotlight so easily. Of all that I have done in my life, I am most proud to be your dad."
When his family joined Obama on the stage, at the close of his farewell speech, they held hands and waved at the audience, creating an image of the family that mirrored a similar one from more than eight years ago, at Obama's victory rally in the same city. But one member of the family was missing: the younger first daughter, Sasha.
And immediately, the Internet noticed. People tweeted in confusion, wondering where the teenager might be.
What could possibly be more important than seeing her father's parting address? They asked and hypothesized.
Soon enough, the answer arrived. She had an exam at school Wednesday morning, a White House official told CBS News. While her family traveled to Chicago, Sasha stayed back in Washington, D.C.
The 15-year-old attends Sidwell Friends, a highly selective school in the nation's capital. On the school's website, a schedule for the Upper School's mid-academic year exams lists a science exam scheduled for 10 a.m. on Wednesday.
Listed on the same page, the exam protocols include guidelines that "students must adhere to the published examination schedule. Absence for travel is not an adequate reason to re-schedule an exam."
Even, perhaps, if the travel is for your father's presidential farewell address?
It is not the first time that Sasha's academic commitments have made headlines. In March, Obama announced that he and his family will stay in Washington for a couple of years after his presidency so that Sasha can finish high school.
"Transferring someone in the middle of high school," the president said. "Tough."