As people approach midlife, the days of youthful exploration, when life felt like one big blind date, are fading. Schedules compress, priorities change and people often become pickier in what they want in their friends… [later] people realize how much they have neglected to restock their pool of friends only when they encounter a big life event, like a move, say, or a divorce.

More fish, sure, but are there always more friends in the sea? In its Sunday edition, The New York Times considers the expansive, but shallow pools of friends, associates, and colleagues–the slackening social networks–so many notice with a start in middle age.

As external conditions change, it becomes tougher to meet the three conditions that sociologists since the 1950s have considered crucial to making close friends: proximity; repeated, unplanned interactions; and a setting that encourages people to let their guard down and confide in each other, said Rebecca G. Adams, a professor of sociology and gerontology at the University of North Carolina at Greensboro. This is why so many people meet their lifelong friends in college, she added.

The article goes on to cite, beyond graduation, increasing couple-dom, divergent careers (even best friends can grow apart when one has mortgage troubles while the other can’t decide whether to spend one month or two in St. Bart’s), parenthood, and the pickiness engendered by self-discovery as reasons adults find themselves with fewer friends–and fewer avenues to find new ones–once they’re out of college and early career stages.

The good news, though, is that social scientists like psychologist Linda L. Carstensen have found that, as friend numbers dwindle (though perhaps not on Facebook), those remaining friendships grow closer.  In fact, Marla Paul, author of The Friendship Crisis, tells the Times, “The bar is higher than when we were younger and were willing to meet almost anyone for a margarita,” but that’s not necessarily a bad thing. People may find that they have just enough time to invest in real, lasting, fruitful friendships with this culled group.

Or, they might follow advice given by others in the Times: go on a search to fill specific “friend niches” or even launch back into the incredibly social, unattached behavior of their early 20s. Exhaustive, to be sure, but quite possibly exhausting.