In a video on YouTube a woman riding the subway begins to laugh at something she’s reading. First it’s an upturn of her mouth and a little ripple of sound. Next it’s nearly wholehearted. What comes next is where it gets really good—one by one nearly the entire car of subway rides starts to laugh. They don’t even know what they’re laughing at. They’re laughing at laughter, with laughter, with each other. Joy permeates even a viewer thousands of miles away and maybe months after the real thing. Sweet contagion!
Sometimes it takes so little, really, to turn a day right side up until our mouths hurt from smiling and our sides ache from laughing, happiness tears running down our cheeks.