Close to a decade ago, I moved to my current city. In my first 3 months in the city, I met the guys who became my core group of friends. We were all living in adjacent apartments, we were mostly new to the city/transplants from elsewhere, and most of us were single. One guy moved here with his college girlfriend. We were all in our 20s. I was the oldest at 28, the rest were 22-24.
Now I'm 37, the other guys are all in their 30s. They are all married, except one guy with the same gf for the past 7 years. We no longer live in adjacent apartments. The guys who were single eventually got married. The guy who moved to this city with his gf eventually married that same gf and moved away. I'm currently single and unattached. Over the years, I've had the most unsettled romantic life.
The group that was very tight in 2011-13 is now disjointed.