“All grown-ups were once children,” reads a passage of Antoine de Saint-Exupéry’s Petit Prince, “but only few of them remember it.” Simplicity. Gravity. Mystery. Among the characters one finds in this otherworldly book there’s the king with no subjects, the businessman who owns the stars, the dutiful lamplighter, the elderly geographer, the drunkard, the narcissist. Each imparts a lesson with lightness. Banned in France by the Vichy Regime, the book was first published in the U.S., in 1943; a French publication came in 1946. This exhibition celebrates the beloved best-selling book with 600 objects. Many of them look to the life of Saint-Exupéry, an aristocrat of many talents: journalist, poet, aviator, explorer, inventor, and philosopher. The original manuscript, usually stored at the Morgan Library & Museum, will be on view. —Elena Clavarino