This harbour seal, photographed at Robert Moses State Park on Long Island in New York, United States, seems to be onto something—spreading good vibes, one wave at a time. That"s exactly the spirit of World Hello Day, celebrated every November 21. This cheerful observance began in 1973 when two American brothers, Brian and Michael McCormack, launched it as a peaceful response to global tensions. They mailed 1,360 letters in seven languages to world leaders, inviting them to join the first celebration. Their message was simple yet powerful: personal communication can help preserve peace. Today, people in more than 180 countries participate.