It's February 2009, and Bill Gates is standing on the TED stage in Long Beach. He's talking about malaria — a subject he knows better than anyone else in the room, because his foundation funds work on a vaccine, on bed nets, and on new ways of killing mosquitoes. He has the numbers down to the decimal point; he's been repeating them in public for years. The disease kills around a million people a year. At any given moment, more than two hundred million people are infected. In some regions, it holds back entire economies. Every time, the audience nods along and moves on to the next item on the program.
This time, Gates stops halfway through a thought and reaches for a jar on the table beside him.
"Malaria is spread by mosquitoes," he says. "I brought some with me. I'll let them out and let them fly around the room a little."
He opens the jar. Sitting in front of him are investors, scientists, and journalists from the biggest newsrooms in the world, and for a moment nobody says anything.
"There's no reason only poor people should have the experience," he adds, and pauses. "Those mosquitoes are not infected."
The room breaks into laughter and applause, and the story is traveling around the world before Gates has even left the stage.
He didn't give a single new number that day. What he gave up was the assumption that the people in the audience felt what he felt when he looked at malaria data — and only then did the subject stop being an abstraction for them. A year later he was back at TED with a talk about the future of energy and pulled the same move, this time releasing fireflies, then walked off to a standing ovation. For most of his career he had been considered a competent speaker at best. Today his talks are textbook material.
The phenomenon Gates sidestepped with a single gesture has a name — and a sizable body of research behind it.
What the curse of knowledge is
The term first appeared in 1989, in a paper by the economists Colin Camerer, George Loewenstein, and Martin Weber published in the Journal of Political Economy. They were looking at why better-informed market participants are so bad at predicting the decisions of people who know less. It turns out you can't simply set your own knowledge aside. Once you know something, your brain uses that knowledge automatically — including when you're trying to put yourself in the position of someone who doesn't have it.
The best-known demonstration comes from an experiment run in 1990 at Stanford by Elizabeth Newton. She split participants into two groups: tappers and listeners. The tappers were given a list of twenty-five very familiar tunes, "Happy Birthday" among them, picked one, and tapped out its rhythm on the table with their fingers. The listener's job was to name the song.
The result is one of the best illustrations of the problem I know of. Out of one hundred and twenty tunes tapped out, listeners identified three — a hit rate of 2.5 percent. Before the answers came in, though, Newton had asked the tappers to estimate their chances, and on average they predicted fifty percent. The gap between one message in two getting through and one in forty is exactly the space where most business presentations disappear.
The mechanism is simple. The person tapping hears the whole song in their head — melody, lyrics, arrangement — so the tapping feels obvious. The other person hears a series of random knocks on a table. The same asymmetry plays out every day in meeting rooms, when an IT director explains system architecture to the board or a financial analyst walks through the assumptions behind a model.
Why it hits the best specialists hardest
On my presentation training courses, the people who struggle with this most are the analytical minds: engineers, financial controllers, data specialists, heads of production. That's no accident, and it has nothing to do with a lack of natural talent for speaking.
Over the years, an expert builds a dense network of concepts in their head, one in which a single word stands in for an entire chain of reasoning. When a maintenance manager says "we have an OEE problem on line three," a dozen connected facts unfold in his mind: availability, performance, and quality; the history of that particular line; what all of it means for the production schedule. A board member hears an acronym he has to stop at, and from that moment he stops listening to the rest of the sentence, because he's busy catching up. The greater the expertise, the more of these shortcuts there are — that's precisely what being an expert consists of.
Then there's something that gets talked about less often. Many specialists treat detail as proof of rigor, so they add another thread, another caveat, another footnote, so that nobody can accuse them of being superficial. The effect is the opposite of the one intended. An audience that gets lost doesn't read the presentation as thorough, it reads it as unclear — and starts to have doubts about the presenter while it's at it.
It's also worth saying that generative tools have deepened this problem rather than solved it. Teams now produce more slides and more reports in less time, while the quality of the thinking behind those materials hasn't changed at all. More content with the same curse of knowledge simply means more noise.
Five signs the curse of knowledge is at work in your presentation
You can't feel the curse of knowledge from the inside — by definition, it's invisible to the person under it. What you can do is spot its traces in the material.
You start with methodology. The first slides explain where the data came from, what the sample looked like, and which assumptions were made. To you, this is the foundation of your credibility. To your audience, it's three minutes of information they have nothing to attach to yet.
There are acronyms and internal names with nothing spelled out. The names of systems, projects, and metrics that are self-evident inside your department and mean nothing outside it. Every one of them costs your audience a few seconds of attention.
There's an entire table on the slide. You show the complete data set, because removing anything feels like cutting corners. What your audience gets at that moment is an analytical task with about fifteen seconds to complete it.
Your slide titles are labels. "Q3 Results." "Risks." "Recommendations." You know what the data means, so to you the title is just a tag. Your audience has to draw the conclusion on its own — at a pace and in a direction you don't control.
The questions afterward are about the basics. When someone asks, forty minutes in, "so what exactly are we deciding here?", you have the cleanest possible evidence that the message didn't land. That single signal is worth more than an entire satisfaction survey.
How to break out of it
You can't unlearn what you know. What you can do is build a process that catches the effects of the curse before the material reaches the meeting. Here are four things that work for me and in my workshops.
1. Start with the decision, not the content
Before you open PowerPoint, write down in one sentence what specifically should happen after your presentation. Someone approves a budget. Someone picks one of three options. Someone understands a change and passes it on to their team. That sentence becomes your selection criterion: any slide that doesn't move your audience closer to that decision is out of the deck.
2. Write slide titles as full sentences
This is the change that delivers the biggest effect for the least effort. Instead of "Q3 Sales Results," write "Q3 sales grew 12 percent on the back of the new online channel." A full sentence hands over the conclusion immediately, and the rest of the slide becomes the evidence for it. You also get a free consistency check: read the titles one after another, and they should add up to a coherent summary.
3. Trade abstraction for something concrete
That's what Gates's mosquitoes were for. Two hundred million cases is a true and important number, but it can't be felt until it's translated into something the audience experiences directly. In a business presentation you rarely need anything that spectacular. It's enough to convert your data into units your audience already knows. Instead of talking about a two-percentage-point improvement in a metric, say how many hours of work a week that adds up to, or what it's worth over a quarter.
4. Find your listener before the meeting
The simplest and most underrated step is to show the material to someone outside the subject and ask for a one-sentence summary. Not an assessment, not corrections — just an answer to the question of what they think this is about. If that sentence differs from your intention, you know exactly where the problem is, and you still have time to fix it. In the teams that have worked this way with me, the most common result has been shorter meetings, because the round of clarifying questions about what the author meant simply disappears.
Why this is an organizational problem, not an individual one
When a company has a run of presentations that fall flat, the first reaction is usually personal: someone can't present. The curse of knowledge shows that what we're dealing with is systematic, and that it affects every expert in every department — just at different moments and on different topics.
From an L&D perspective, this has two consequences. The first concerns program selection: public-speaking training teaches the stage, the microphone, and confidence, whereas the curse of knowledge takes hold a few days earlier, while the structure is being built and the content chosen. The second concerns measurement, because the results of this kind of work can be shown to the board without any complicated methodology. All it takes is a side-by-side comparison of the same team's presentations before and after the program, plus meeting length and the number of clarifying questions.
That, incidentally, is the argument that works best in a conversation with the board. You're not talking about developing soft skills. You're talking about shortening the path to a decision.
Frequently asked questions
Does the curse of knowledge only apply to technical subjects? No, although technical fields are where it shows up most clearly, because that's where the knowledge gap between speaker and audience tends to be widest. The exact same mechanism operates in law, in HR, and in marketing — anywhere someone has spent years working with the same set of concepts.
Doesn't simplifying the message undermine an expert's credibility? Credibility is built on understanding, not on volume. If you're worried about being accused of superficiality, keep the full data in an appendix or on backup slides and return to it when someone asks for detail. You're taking the data off the screen, not out of the analysis.
How long does it take to escape the curse of knowledge? You never escape it once and for all, because it comes back with every new subject you become an expert in. What you can do is build two or three checkpoints into your preparation process. Together they take about fifteen minutes, and they catch most of the problems.
Does AI help or hurt? Both, depending on how you use it. Ask a model to generate slides and you'll get more content built on the same thinking structure. Ask it to summarize your material in a single sentence and compare that with your own intention, and you have a cheap, fast test of what your material actually says.
Where to go from here
The curse of knowledge doesn't come from a lack of presentation skills. It comes from knowing too much to see your own material through your audience's eyes. Newton's experiment shows the scale of the problem: fifty percent expected effectiveness against 2.5 percent actual. Gates's story shows that it can be reversed without changing a single data point and without turning yourself into a showman.
Three things worth remembering. Start by writing down the decision your audience needs to make. Write slide titles as full sentences that state the conclusion. Before you send the material out, show it to someone outside the subject and ask for a one-sentence summary.
And if you'd like to build this way of working into an entire team, let's talk about a training program designed around your real presentations.
Piotr Garlej
