Surely you’ve been there.
You have a complex problem to solve. You’ve done the work. You’ve already tried a several solutions. None of them have moved the needle.
You vow to think about it for a day. One day becomes forever. It isn’t that you didn’t care about the problem, but a bigger problem imposed its will. And your attention moved on.
There are countless ways to remind yourself to return to the problem, but there is an associated discipline to burning down your TODO list.
If you are working with others on the problem, the fatigue hits everyone. Attention dwindles as the problems grow.
I don’t know the solution. I’m living this in real-time. Maybe I need to follow my own advice.