I am currently reading '30 lessons for living' by Karl Pillemer and one chapter is about aging fearlessly and well. Most elderly realized in hindsight that they imagined being old as a terrible thing. They feared getting older by the age of 40 because they felt what you describe: life seems to get more serious and more boring. Friends don't want to party like they used to do.
One of the advices of the chapter was the following:
4. Stay connected. Take seriously the threat of social isolation in middle age and beyond, and make conscious efforts beginning in middle age to stay connected through new learning opportunities and relationships.
I am currently trying to adapt that to my own situation. 31yo post 2 years of Corona isolation. I just signed up for volunteer work and a rowing club and life feels fun again :)
Yes, this is very true. My experience is that as you get older you make fewer new contacts. It's not illogical, at first there is school, then university, then kids. All of these are excellent at making new friends but once the kids get old enough you stop naturally meet people outside of work, at least you have to put in some work for it to happen. I realized the other week that if I would not have my wife, it would easily be weeks between having a somewhat deep discussion with anyone outside of work. It's a terrifying thought.
I am currently trying to adapt that to my own situation. 31yo post 2 years of Corona isolation. I just signed up for volunteer work and a rowing club and life feels fun again :)