On a warm summer morning in Paris, a sprightly old man clutching a bouquet of red silk roses and dressed in a large plaid jacket over formal clothes, hobbled slowly through the doors of the Louvre. The security guards nodded as he passed. He walked unhurried past many paintings, completely sure of his destination, never once glancing at a map. When he saw the Mona Lisa, he stopped and his face broke into a beaming smile.

“Bon matin, ma petite fille.” He laid the roses on the floor under her picture. Seemingly satisfied with her response, he sat nearby and continued to smile at her.

A newly hired guard wearing a name plate that read “Didier” walked up to the old man and asked him why he had given flowers to a picture. The old man turned to him and explained that Leonardo had told him to take care of Lisa, to keep her happy, and to make sure she was always smiling. The roses, he added, were her favorites. The young man nodded, not for a moment believing the man, but allowing him to continue his ritual.

Not even a year later, the old man suddenly stopped visiting the museum. The change came as a shock to the museum staff as he had been a regular presence for decades. When some of them tried to find him—which proved to be difficult when they didn’t know his name—they were told that he had died. Everyone at the museum, even those who had only seen him once, mourned his passing and decided to hold a memorial service.

The day of the service, Didier walked past the Mona Lisa, realizing that he would never again see the little smiling face sitting near her. He stopped. The painting looked strange. Something was wrong with her smile. Leaving immediately, he went out and bought a dozen roses and placed them under her picture. The Mona Lisa smiled again.