A laser is narrow. That's the entire point of the metaphor, and it's the part people skip.
Focusing on one thing today means other things don't get done — messages unanswered, someone mildly annoyed, a small fire left to smoke. If nothing is being neglected, you aren't focused, you're just busy.
So decide what the one thing is, and then decide what you're willing to pay for it. Focus without a cost list tends to collapse by eleven in the morning.