Why what you know feels obvious.

In 1990, Elizabeth Newton, a psychology PhD student at Stanford, asked people to tap out well-known songs on a table and guess how many listeners would recognize them. The tappers guessed about half. Out of 120 songs, the listeners named three: 2.5%.¹

The explanation is simple, and frustrating. The tappers heard the melody in their heads. The listeners heard knocking on a table.

It has a name

A year earlier, three economists, Colin Camerer, George Loewenstein and Martin Weber, gave it a name: the curse of knowledge. Once you know something, it's hard to reconstruct what the world looked like before you did.²

The philosopher Michael Polanyi put it even earlier, in 1966, in a single line: we know more than we can tell. We ride a bike without explaining the physics, and recognize a face without knowing how.³

Why it happens to the best

The longer you do something, the more of it moves into your hands. A chef doesn't think about the angle of the knife. A designer doesn't debate whether the spacing is right, she just sees it. What used to be a decision turns into a feeling.

And that's exactly the problem when you want to pass it on. The feeling doesn't come with instructions. From the outside it looks like talent, and from the inside you don't notice it at all.

What feels obvious to you is what took you years to understand.

What still doesn't transfer

To be fair: not everything you know belongs in a course, and some knowledge really does pass only next to someone, in a room, over time. In some fields, hands-on mentoring won't be replaced.

And Newton's study doesn't say you can't explain. It says the person who knows needs help hearing themselves from the outside: someone who doesn't know yet, who asks the right questions and hands the melody back to you in words.

How to hear the melody from outside

Notice the questions that repeat. What people ask you again and again is what they can't see on their own, and that's exactly where your knowledge is worth the most.

Notice what you do without thinking. The step you skip when you explain, because "obviously", is usually the step the learner needs most.

What this says about you

If you think you don't have enough for a course, because "everyone knows that", be suspicious of the feeling. It comes from the same place that made the tappers believe everyone would hear the song.

The listeners named three songs out of 120. The songs were good. The melody was just with the person tapping.