If you take the habit of crushing your uncertainty, your model of situations can be much simpler and you won't have to deal with residual uncertainty from previous related investigations. Instead of many possible worlds and nuanced probability distributions to remember and gum up your thoughts, you can deal with simple, clear, unambiguous facts.

I think of it as making decisions. If there's "30% chance of rain", you can't take 30% of an umbrella. You either take one, or not, and the decision turns out to be right, or not. Uncertainty is continuous, decision is discontinuous.

Decisions are not made only at the end of reasoning out a situation, but all the way through, as you discard possbilities when they appear not to be worth further attention. For that matter, sometimes you have to discard possibilities that are worth further attention, because you can't explore everything in order to decide which things to explore.