I do not understand this part

In a diwaniya in Kuwait, the conversation turns to why a shop on the corner closed after eight months.

Within a minute, three men have the answer. It was the rent. It was the parking. It was the owner's nephew. Each delivers his verdict with the calm of someone who has studied the matter for years. None of them has ever run a shop, and none of them spoke to the owner.

This has become normal, and not only in sitting rooms. A complicated problem arrives, and the socially acceptable response is to sound sure. Confusion is treated as weakness, so people dress it up in a firm voice and a tidy explanation.

The trouble is that a confident wrong answer is very hard to learn from. If I am already certain why the shop failed, I have no reason to ask the owner, no reason to look at what the neighbouring shop did differently, no reason to change my mind. And when my own plan, built on that certainty, goes wrong in turn, I will usually find a new certainty rather than a question.

Saying the honest sentence is far more useful. I do not understand this part. It sounds smaller in the room. It is also the only sentence that invites somebody who does understand to explain it.

The people I trust most on any hard subject say it often. Not because they know less, but because they have noticed that the admission is where the learning starts.

Certainty feels like progress. Most of the time it is just confusion that has stopped looking for help.