Joyce N. Boghosian / White House Photo

"Our greeter as 7-year-olds at our grandfather’s Inauguration was Nancy, the White House florist, who ushered us in from the cold," they said. "She helped us make colorful bouquets of winter flowers for our grandparents’ bedside. Twenty years later, Nancy did the flowers for Jenna’s wedding. Cherish your own Nancy."

"We stay in touch with our Secret Service," they added. "They were part of growing up for us: there for first dates, first days and even an engagement and a honeymoon. We know it wasn’t always easy — the two of you and the two of us were teenagers trailed by men in backpacks — but they put their lives on hold for us."