So I've learned that I get a funny stare when I head into my imagination and start to dream up a story. I'll just be sitting there, having coffee and talking to my husband and all the sudden the conversation will lull and I'll catch myself staring into the distance (usually at my bookshelf--inspiration?) and realize that in my mind I'm on the Alaskan tundra, plotting all kinds of mayhem.
Sometimes it's inconvenient to have an overactive imagination. When I was a kid and 'what-ifs' and bad dreams kept me up? It was definitely inconvenient. When I'm trying to talk to someone and get distracted by a new plot angle that pops into my head? That's moderately inconvenient too. But I do like how easy it is to get into my story-world MOST of the time (some days it just doesn't work) so I can multi-task.
Having time to write and having time to live life are both super important. If you chain yourself to your computer for 12 hours a day, you'll eventually run out of inspiration because you won't really be living. Besides that, I know we're all busy. We don't have 12 hours to sit and wait for the ideas to come. So how can you build time to write, or plan your story into your day?
Can you work on character development and ask your characters questions about themselves while you fold laundry and remember to write down what you've learned later?
If you're in school, could you work on your plot while you're walking to your next class? While you're putting on your makeup?
We've all got little bits of time throughout the day when we can find a minute to dream, to get lost in our imagination. Find those times if you can and see if it helps you be more productive when you do get a minute to sit down to write!
Just maybe don't brainstorm while you're driving unless you have really good concentration. That could get dangerous in a hurry. ;)