And while we're amplifying…
Personally, I'm very fond of the military concept of OODA. Observe, Orient, Decide, Act. In the early Naughts, it made its way into corporate management as the buzzword of the week and subsequently into the rah-rah speech that you probably have heard at least one TED talk. Not surprisingly, when it was no longer the fad term of the moment it became something that was no longer trendy and thus must be denigrated.
But the original idea, that the OODA loop is a descriptive tool for looking at systems remains useful. The decision-making architecture of human consciousness is a system. So let's look at what the "act" is in the context of deciding what problems not to solve.
Obviously the act itself is the decision. But the decision is the last part of the loop. What comes before that?
First we observe that a decision will have to be made. In particular, making the decision of what problem you don't tackle comes up all the time. It's a constant loop. At any given moment, you are deciding what issues have priority in your observational field.
Next, you orient. You gather information. You look at what resources you have at your disposal. If you aren't doing this before you decide what problems not to tackle, you're probably wasting a lot of your energy taking on problems you don't know how to solve, you don't have the resources to solve, or don't need to be solved. Orientation is the part of the loop that puts us in a position to act.
Then comes the decision, though in this case it's more of a meta-decision. You have decided on what your decision should be. A lot of people get hung up at just this part of the loop. They recognize the decision will have to be made. They look at their resources and look at their priorities. And then they simply can't decide to make a decision. Sometimes they're afraid of what will come about as a result of their action. Sometimes they have been taught to constantly question themselves to the point where they have analysis paralysis. Sometimes they've simply been conditioned against making decisions, contaminated with the idea that judgment is somehow inherently wrong. This is the moment at which events often move faster than they are willing to decide on.
And then comes action. The action of decision, the execution of priorities, and the finalization of choice. This is the moment it which having decided that a problem is not yours to solve for whatever reasons, you consciously set it aside and move on to something else.
Taken as a whole, the OODA loop shows you with a recursive level of detail what the last step in the next step is at every point. If you find yourself not able to figure out what problems not to solve, think about the steps in the loop and think about which of them is giving you a problem.
Then you can refine that part down to a fine gloss and move on to the next decision.