A Taiwanese schoolboy, 12, did just that on a visit to a Leonardo da Vinci-themed show in Taipei, tripping up while admiring the exhibits.
When he put out his hand to steady himself, he tore a hole "the size of a fist" in a $1.5 million artwork.
"The boy was probably too concentrated in listening to what the guide was saying, and therefore stumbled," said Sun Chi-hsuan, one of the exhibition's organizers.
The incident, at Taipei's Huashan 1914
creative arts center, was captured on closed-circuit television footage from inside the gallery.
"Flowers," by 17th-century Italian Baroque artist Paolo Porpora, was one of 55 pieces on display in "The Face of Leonardo, Images of a Genius
But Sun said the cost of repairs to the damaged painting would be covered by insurance, meaning the boy and his family won't be asked to pay up.
"I'm actually thinking of asking the boy back to be a volunteer in the exhibition for one day," Sun said, "as a penalty."
The painting is undergoing restoration by experts in Taipei.
"We will begin the restoration work by ... mending the part that was torn on the back," said Leo Tsai, a fine art restorer. "We will then turn to restoring the paints on the front side."
Curator Andrea Rossi was left dumbfounded by news of the accident, according to Sun.
"When I told the curator, he was so shocked that for two to three minutes he couldn't utter a single word," Sun said. "But he was actually most worried that the boy and his family would put too much pressure on themselves."
Before the show began, Sun said the curator gave its organizers special approval to allow visitors closer access to the paintings on display.
"This is a one-off accident," Sun insisted. "I believe if viewers are placed so far away in the distance that the paintings won't be destroyed if someone stumbles, they won't be able to appreciate the paintings to the full extent."
Since news of the accident, visitor numbers at the show have gone up, but the restricted area in front of each painting has been enlarged to prevent further mishaps.