Some months ago, I read of FOMO. I am not up on the latest expressions but I was curious so I looked up "FOMO". What I found said that the letters stood for "fear of missing out". I think that sort of worry can pop up when I hear that a wonderful party was held but I hadn't been told or invited.
We have many ways of communicating these days and information about an exciting event can be sent by email while I am only looking at Facebook. Lynn and some other women have devotedly used US Post for communication once a month for decades. They know they could send a text message but they want to stick to handwriting on paper that gets put into an envelope, stamped with a US postage stamp and mailed. I might develop FOMO when I find out that people I know talk on Google Voice but I don't check that service.
Anyone who uses tv or the internet or borrows books from a library can actually see that they aren't keeping up and cannot. Viking and Elderhostel/Road Scholar make it clear that there are many parts of the world I have not visited.
The more I estimate and calculate, the clearer it becomes that whether I have a fear or not, I am going to miss out on many trips, books, friends, movies, etc. I have several thousand Kindle books, many that I have never opened. Each Monday, I can go online using https://libbyapp.com, the app/program called "Libby" and see more than 12,000 books I can borrow for free. Netflix offers me 3700 movies I can watch.
I am moving away from any fear of missing out and improving my acceptance of my gorgeous limitations of time, patience and interest.