Interacting with real people, facing a person trying to get help for something that they don't want to experience is vastly different than reading about a symptom or group of symptoms in a book.
Doctors, from what I can tell, receive no formal education in nursing.
Seriously ? ¯\_(ツ)_/¯
The textbooks are the theory.
The hospital wards are the practice.
The hospital wards are what shows you that the human body is complex and many times things don't happen like the textbook says it will.
And then there's the ICU, pediatric, geriatric and mental health wards where the patient often cannot even describe their symptoms ...
In practice...