The curse of knowledge is the cognitive bias where a person who has expertise in a subject assumes that others share their background knowledge — making it difficult to communicate effectively with those who lack the same information.

The Core Problem

Once you know something, it's nearly impossible to remember what it was like not to know it. Expert knowledge is tacit — so embedded in your thinking that it's invisible. You communicate from your current state, not from your audience's starting state.

Classic Demonstration

In Elizabeth Newton's 1990 experiment, "tappers" tapped out famous songs while "listeners" tried to guess them. Tappers predicted listeners would guess correctly 50% of the time. Actual accuracy: 2.5%. The tappers could hear the music in their heads; listeners heard only taps.

Where It Causes Damage

• Technical documentation written by engineers, unreadable by users
• Teachers who can't identify where students get lost
• Leaders who communicate strategy without the context that makes it obvious
• Designers who assume users understand interface conventions

Fix

Test your communication on someone from your audience's knowledge level before deploying it widely.

Reference:

Wikipedia: Curse of Knowledge

https://en.wikipedia.org/wiki/Curse_of_knowledge