Yeah, countries like Denmark and Sweden (Norway too I think) often register at the top of these lists which I think are based on things like access to health care and general standard of living. Should be called ”Most Priviliged Countries In The World.” Being northern European countries, Sweden and Denmark are culturally inclined to be somewhat restrained, reserved and, I dunno, aloof?. If you've lived here you'll know what I'm talking about! The Spanish or Italians as a people, seem way happier!
Dude, I can't find it but a Dane WATMMer pointrd out that "happy" poll is misleading. The way it was asked/translated actually is closer to "content" and not happy. Still highly ranked but less utopia vibes. Which makes sense because it gels with the cultural and social trends of Scandinavian countries. A good example is how people in those countries usually stand really far apart in queues and bus stations.
This is true