On that first mission, Tibbets saw in real time that his bombs were falling on innocent civilians. At the time, he thought to himself, "People are getting killed down there that don't have any business getting killed. Those are not soldiers." But then he thought back to a lesson he had learned during his time at medical school from his roommate who was a doctor. This doctor explained to him about his former classmates who failed the program and ended up in drug sales. The reason why they had failed the program was because "they had too much sympathy for their patients", which "destroyed their ability to render the medical necessities". It dawned on Tibbets that: