Not sure how this happened, but I don't have any friends.

So it struck me the other day that I don’t have any friends.

OK, that’s a little melodramatic, I guess. But I can say quite honestly that compared with my life a few years ago, my life now is decidedly quieter, and I’m missing the people who once made it so rich.

My sister, a therapist, says for most of us, the majority of friends tend to be situational: Our friends are the people with whom we go to school, or with whom we work. Later, they’re the people whose kids go to school or are on sports teams with our kids.

That makes sense; we spend time with those people. We have common interests, and the friendships tend to last as long as we have those interests in common. And my kids are grown now, so my stage in life limits my options.

There are exceptions, of course. Before we reached an impasse a few months ago, I had a friend – a best friend, I guess you’d say – and our relationship had persisted through moves and job changes and family crises. But there had been issues, and I had swallowed my feelings about a few things, and finally I couldn’t swallow them anymore. After a very direct conversation, we mutually agreed, without saying as much, to part ways. And as sad as that was, it was a healthy decision that needed to be made.

There are a few others exceptions: a couple of women who live in other cities, one with whom I’ve been friends since high school, and another who has been a loyal friend since my days as a lowly newspaper intern. I know each of them would offer me comfort and support at a moment’s notice, but it’s not as if I can call either of them up and suggest a trip to the mall. And I do have a long-time friend who doesn’t live far away, but is busy and prefers to spend her free time with her husband.

I know I’m not the only person in this situation. By this point in life, most of us have collected an assortment of acquaintances; like many others, I can’t go to the store without running into several people I know. But would I call any of those people to share a problem or a joy? Nope. We say, “We should get together sometime,” but we know that probably won’t happen.

And I love my social-media friends; that’s a whole other category, because when I’m on Facebook, I feel the warmth and support of real friendships. The problem is: Many of them, again, aren’t local. And others are people I’d like to be “real” friends with, but I can’t just inject myself into their lives.

What is this phenomenon? As my sister says, it’s probably situational. But I think there might be something else at work.

My life looks like this: I work full-time and freelance on the side. Within a couple of months, I’m going to start leading a Weight Watchers meeting every week. I have a husband, two grown children, three grown stepchildren and a teenage stepson, and a 2-year-old step-granddaughter. I have an extended family and a dog. I work out, I travel a little for work, and I try to stay on top of a bunch of reading (and often fail miserably).

So at the end of the day, I’m tired. Face it: I’m not 20. I spent years and years working at one job all day, then going to cover meetings and write stories for another, so I’m happy to go home after work. I’m also not much of a partier; this tends to limit me socially, as so many activities seem to revolve around drinking. (To be clear: This isn’t a judgment call; I just don’t enjoy the taste of alcohol or the way it makes me feel.)

And I think many of us are in the same boat. Our lives are full, and we’re tired. On a Friday night, going to bed early can sound a whole lot more appealing than going out for a beer. So our social lives take a back seat, and our relationships with people outside of our families suffer.

There’s also something else that’s a little harder to address: Many of us, when we get to a certain point in life, have fully formed our ideas about the world we live in; we’re not on the fence about politics or religion or social issues, and we’re not shy about sharing our opinions. True friendships can be difficult with people who have strong opinions that directly oppose ours. Those relationships are not impossible, and I don’t for a minute think everyone should believe the way I do. But friendships shouldn’t be fraught with arguments about ideals we hold dear; it’s just too hard.

Don’t get me wrong: I’m unbelievably fortunate, and I count my blessings daily. My adult children seem to enjoy spending time with me, and I treasure those relationships above all others. I’m married to a man who makes me laugh; he works hard and also feels tired much of the time, so he’s fine with staying home. And as I’ve focused on my health the past year, I’ve met some wonderful new people with whom I’m spending a little time each week. Those budding friendships give me hope.

But I feel a pang as I watch my daughter live her life and I see how dear her female friends are to her, especially as she begins to plan her wedding. And I think back to the first time I was married; I had seven bridesmaids because I couldn’t possibly have excluded any of the important women in my life.

And I look around now, and those relationships – and those voices, and that laughter – are just not here anymore.  And while my life is by no means empty, there’s a void.

I know and believe the saying, “To have a friend, be a friend.” I know friendships don’t just happen, and I know I haven’t worked on them. So the onus is on me to change things. But have I forgotten how? It’s not as if I can just show up on someone’s doorstep with my Barbies or “Mystery Date” game.

Be warned, then: If you know me well enough to say “hi” to me in the grocery store, I may call you up and ask you do go to the mall. If you humor me and go, I promise not to write any more whiny blog posts.