I've been thinking — and this is no way an original idea, but I've been thinking it anyway — about how one of the (perhaps necessary?) components of creativity is the ability to let the creative work occupy your thoughts.
Or, more specifically: the ability to let the creative work be the problem your brain tries to solve in the shower.
We already know that our brains do a lot of excellent problem-solving work while they aren't focused on other stuff; this is why we get insights in the shower and on walks and while we're unloading the dishwasher and when we wake up at 3 a.m. to a brain that's all "I figured it out! Now write it down or I won't let you go back to sleep again."
(Or, sometimes: "I'm upset that I haven't figured it out yet! Let's do some thinking RIGHT NOW or I won't let you go back to sleep again.")
But I've found that my brain likes to concern itself with the biggest problem in my life at the moment, and if there is a problem that's more important than NEXT BOOK, that's the problem that my brain's going to want to tackle when I'm not focused on anything else.
I am very good at focusing on work even when there are larger issues going on in my life or in the world. I can tell myself "this is the discrete task I need to complete right now, and I'll still be in the emergency room/I'll still have that meeting where I have to have the difficult conversation/Trump will still be president when I'm done."
But I don't know how to control the problems my brain wants to solve afterwards.
The thoughts that occupy my thoughts.
I just finished reading Cal Newport's Deep Work: Rules for Focused Success in a Distracted World, and he and David Allen and everyone else notes that open brain loops are huge mind-sucks (and yes, I'm using "suck" in the colloquial way here).
Newport references the thing where you check your email on Saturday morning and learn that there's some unresolved issue or difficult conversation or large task that you won't be able to tackle until Monday, and so your brain wastes the whole weekend chewing over the problem and rehearsing fictitious conversations and wondering what might happen and analyzing all of the potential outcomes.
He suggests creating a "shutdown ritual," as follows:
To succeed with this strategy, you must first accept the commitment that once your workday shuts down, you cannot allow even the smallest incursion of professional concerns into your field of attention.
In more detail, this ritual should ensure that every incomplete task, goal, or project has been reviewed and that for each you have confirmed that either (1) you have a plan you trust for its completion, or (2) it's captured in a place where it will be revisited when the time is right. This process should be an algorithm: a series of steps you always conduct, one after another. When you're done, have a set phrase you say that indicates completion (to end my own ritual, I say "Shutdown complete"). This final step sounds cheesy, but it provides a simple cue to your mind that it's safe to release work-related thoughts for the rest of the day.
I'm going to start integrating shutdown rituals into my own work, but some work problems are too large to be shut down at the end of the day (ASK ME HOW I KNOW) and even though I was able to do some excellent thinking on my current work problem over the weekend and come up with a potential solution, that's all time I wasn't spending on NEXT BOOK.
Or anything else.
Which makes me wonder if people can only tackle a large creative project if they don't have any more-important problems for their brains to solve.
I'm not saying "if they don't have any more-important issues in their lives," btw. People do creative work during births and deaths and illnesses and unemployments and all kinds of things.
But if the problem is still an open loop, if it hasn't resolved into a stasis or a plan of action, if the issue is not "okay, we're going to do X and it will be time-consuming and no fun but that's just how our lives will be right now" but "what are we going to do about X, there are ten options and twelve difficult conversations ahead of us," is it possible to not let those thoughts occupy your thoughts?
I don't know.
I'd be interested to know how your brain deals with these kinds of situations.