Writing is a solitary endeavour, but even Batman leaves the Batcave now and then. With the discipline required to get your butt in the chair (BIC) every damn day, and the full attention (to say the least) that most projects require, especially near the end, it's easy to forget the rest of the world. Sometimes it even feels like you're supposed to forget it. Nothing could be farther from the truth.
The world, with all its interruptions and annoyances, is what fills the writer up and enables them to write full-bodied, believable fiction. How can you write about the relationships of your characters, if you don't have any? How can you deal with the conflict between what your protagonist wants and everything else pulling at them if your life is a one note song?
Of course, we all fall into the trap now and then. The trick is to recognize it before it requires medication. Make dates with your spouse/lover. Plan weekend outings with your family. Try new things you've never done before. Your writer bone will be nervous as hell, but you'll actually be strengthening it.
I also find that when I've hit a wall and can't find a solution, getting away from the problem and doing something ordinary and mundane tends to magically solve it. Mow the lawn, paint a room, wash the car...whatever. It may not feel like it, but your writer bone -- which is in the back of your brain between the desire to put melted cheese on fries and daydreams about Missy Peregrym -- will still be chugging away on the problem and thankful that you got your interfering conscious fingers out of the way.
And when those days/weeks do come up where you need to roll the stone over your cave's entrance to hit a deadline, your family is going to be a lot more understanding. And your fiction will be that much more relevant, layered and accessible.