WRT the decline with age, I've always felt like a lot of it is 'ego based', for lack of better terms. I've found that as time goes on, people are far more concerned with doing things by the book, projecting an image, etc. rather than just 'being', enjoying life in the moment, doing things just because. I've certainly been guilty of this to some extent because it seems impossible to avoid. Personal anecdote: At age 16…
I've observed the same but interpret it differently. Life gets more differentiated as you get older. You learn what makes you happy and what doesn't, you experience different situations and react to them, and you make decisions about who you're going to be and what you're going to do. And all of that becomes part of your identity. It's part of your accumulated self-knowledge. And part of that is perceiving difference…
The photograph in the linked article explains it quite well to me - regardless of how 'real' it is, there's a picture of a shiny gathering with the dresses and the shiny clothes and the fancy food, and so on.
And there's nothing wrong with that. I love me some good dress-up and the food there looks super yum. But the simple gatherings seem to have disappeared. Outside of family, do people visit just for the sake of visiting anymore?
I think it was the unified purpose, the school catchment area, maybe. That proximity. Everyone is everywhere now. My park is not your park, my pub is not your pub, etc.