Coca-Cola pulled off one of its most heart-warming stunts in the most unlikely place: a packed metro where nobody even looks up. One stranger opens his tablet, and suddenly bursts into a laugh so ridiculous you have to turn your head. Within seconds, the whole compartment is trying to hold back giggles, and then suddenly they’re all laughing together. Complete strangers connected by nothing but a moment of shared joy. And that’s exactly the point. With one planted laugher and a train full of uns