Adam Mosseri was on a family vacation in Italy last November when he learned he'd have to go toe-to-toe with Elon Musk. The mercurial Musk had just taken over Twitter. Amid the ensuing chaos, Mosseri's boss at rival Meta smelled opportunity. CEO Mark Zuckerberg and other Meta executives wanted to woo creators from Twitter to their social networks. Mosseri, who runs Instagram, paused his holiday to take Zuckerberg's call.Subscribe to The Post Most newsletter for the most important and interesting