Every time Argentina's national team plays, the country has forty-five million head coaches. We all know who should have come on, who should have been subbed off and why the substitution came too late, with a confidence the real coach, who has been doing this for thirty years, almost never shows at a press conference.
In 1999 the psychologists Justin Kruger and David Dunning published a study where the people who performed worst on tests of humor, logic and grammar greatly overestimated their own performance. That's where the Dunning-Kruger effect comes from: someone who knows little about a subject tends to overestimate what they know, precisely because they lack the knowledge to notice what they don't know.
The study has its critics, and some researchers argue that part of the effect is a pure statistical artifact. Still, at work the scene is pretty easy to recognize.
The person who estimates two days for something the senior won't even dare to estimate. The stakeholder who read a thread on X and already knows the right architecture. The one who just learned a framework and wants to use it for everything. The one who looks at a ten-year-old system from the outside and says "I could rewrite this over a weekend".
On the other side are the people who know a lot and have doubts. Who answer "it depends" because it really does depend, and who see the edge cases and everything that can go wrong. Those people sometimes sound less convincing than the one who doesn't doubt, and if on top of that they feel like a fraud, we're in impostor syndrome territory.
Things get serious when the organization rewards confidence. In a meeting, whoever speaks with certainty sounds more convincing than whoever says "I'm not sure, we'd have to try it". And if decisions get made based on who sounds most sure, we leave out exactly the objections worth hearing.
I care more about someone being able to explain what they know, what they're assuming and what they still need to check. Asking "how sure are you?" and then seeing whether that confidence made sense. Asking for estimates as a range instead of a number. And making "I don't know" cost nothing, because on a team where we can fail, doubt becomes information.
That goes for us too, by the way. When something seems obvious and super easy to you, ask yourself whether it's really easy or whether you just don't understand it well enough yet to see the hard part.
The forty-five million coaches don't hurt anyone, because none of us gets to pick the squad. The problem is when the one yelling from the stands is the one picking it.