What does Charlie realize about dr.nemur and Strauss on May 15?

On May 15, Charlie realizes that Dr. Nemur and Dr. Strauss, who performed the surgery that increased his intelligence, view him more as a subject of experimentation than as a person. He becomes aware that they are more focused on the scientific aspects and results of the procedure rather than his feelings and well-being. This insight leads him to feel a sense of betrayal and highlights the ethical implications of their actions in his transformation.