The curse of knowledge is when you know something too well to be able to explain it to others, who aren’t as familiar with it.
The curse of knowledge is a cognitive bias that occurs when an individual, communicating with other individuals, unknowingly assumes that the others have the background to understand.
— Wikipedia
For example, in a classroom setting, teachers have difficulty teaching novices because they cannot put themselves in the position of the student. A brilliant professor might no longer remember the difficulties that a young student encounters when learning a new subject.
— Wikipedia