Seneca isn't simply saying that experience teaches better than textbooks—he's suggesting something more uncomfortable: that formal instruction might actually distance us from truth. A surgeon can memorize every anatomical diagram and still freeze during her first real operation; only the patient's body, with all its particular suffering and resistance, becomes her true teacher. What makes this radical is that it inverts our usual hierarchy, placing the messy, unpredictable world above the orderly systems we build to explain it. He's warning us that we can mistake knowing about life for knowing life itself.