When you’re thinking, you internally articulate some of your thoughts in full while leaving others unfinished.
The ones that you articulate in full, you learn from and use to guide your actions. You should therefore fully articulate as many of your important thoughts as you can.
However, leaving a thought unfinished isn’t necessarily a bad thing. You can anticipate the conclusion of some thoughts without having to fully articulate them, and others just aren’t important enough to warrant full articulation.
The danger lies in those thoughts that you leave unfinished despite knowing that they’re important, and despite not knowing their conclusion. When you do this, it’s often because you’re trying to ignore the reality that you anticipate a fully articulated thought will show you in order to protect yourself from short term pain.
But it’s exactly those thoughts which, if you force yourself to fully articulate them, enable you to achieve the greatest progress after fighting through the pain.