From Newsweek:
Elon Musk has shared a cryptic message that has sparked a flurry of public reaction. “Whoever said “money can’t buy happiness” really knew what they were talking about,” the richest man in the world wrote on X, the platform he owns. The message was followed by a sad face emoji. The adage “Money can’t be happiness” has been cemented in the cultural lexicon for centuries, and can be traced back to the 18th century philosopher, Jean-Jacques Rosseau. It means that while money can provide comfort and security, it cannot guarantee genuine happiness, fulfillment, or emotional well‑being, which come from non‑material aspects of life such as relationships, purpose, and inner peace.