I have fairly narrow interests. I will be the first to admit that. When left to my own devices, I don't tend to do much outside of those very narrow interests. Call it inertia or "internal focus" as I've sometimes referred to it. That works great if you live alone, but not so great when you have a wife and kids.
Before my wife and I got married, or maybe it was early in our marriage, my wife told me there were certain things that she, quite simply, wasn't interested in talking with me about. The minutia of my workday was one of them. Some of my geek projects are another. She doesn't share my passion for technology and I have done my best to respect her wishes and not share. Over time, this has evolved into a more general rule: If what I am doing doesn't directly affect her or the kids, she not only doesn't need to know about it, but doesn't want to know about it.
The problem with this rule is that outside of stuff going on with the kids, schedules, home administrivia, and maybe the occasional program on TV, there isn't much to talk about with my wife. My wife doesn't do much beyond stuff related those tasks, so it's difficult for me to latch onto something to even try to talk to her about. With kids around, it's hard for us to have a conversation even we do have one. We don't have a whole lot of "alone time" as there are just some things that can't be done with the kids awake. It doesn't leave a lot of time for "alone time" and without much to talk about, what "alone time" we have is spent in bed sleeping.
However, I have a different "life" as it were, most of which happens in my office during working and late-night hours. This is stuff, by my rule above, I am unable to share with my wife. Most of it is of little or no interest to her. If she's going to tell me "why the hell are you telling me about this," why bother to tell her? I've just wasted her time and mine. About the only time I'll tell her is if she asks, for example when I show up in bed at 3 or 4am instead of a more normal 1 or 2am. And even then it's one or two sentences at most.
I sometimes wonder if I am making a big deal over nothing. It's not as if our relationship is bad. We can usually have a reasonable conversation, though on sensitive issues, emotions can sometimes get involved on one or both sides. We can usually resolve our differenes and move on, and I assume that happens in any relationship. One thing I can say is that our relationship seems to be missing something.
This is a topic I will have to explore more another time.