VENICE — So you are a young college student, American, on your first whistle-stop tour of Europe. You have fought through the multitudes in front of the Mona Lisa and “Las Meninas,” tried to concentrate on the Sistine Chapel ceiling as the tour groups jostle you. But when you wash up here in the lagoon, and make your way to the Scuola Grande di San Rocco — a 16th-century clubhouse for middle-class Venetians — you step into something you’d forgotten: silence.

Inside there are fewer than a dozen people, and all around you, in the half-light, are some of the boldest paintings of the Italian Renaissance, depicting the life of Christ with a directness you have never seen before. You gasp before the burly bodies that loom amid shearing bolts of white and divine blasts of amber. You walk out of San Rocco half an hour later, and the light outside seems too bright. Everything you thought you knew about painting is wrong.

Some people’s whole lives get upended when they first discover Tintoretto, the most Venetian of artists and the world champion of painterly turbulence. The Victorian art critic John Ruskin nearly fainted outside San Rocco. Henry James became ecstatic. Today, some visitors are reduced to tears. Tintoretto left me powerless, too, when I first visited San Rocco in my youth, and did so again for different reasons this October, just before record flooding turned St. Mark’s Square into a swimming pool.