Bill Gates shared this insight after describing a visit to a South African hospital for patients with multi-drug resistant tuberculosis — a place he called 'hell with a waiting list.' Rather than being defeated by the suffering he witnessed, the experience channeled his optimism into action. He told the doctor they must do something, and by the time of the speech, a new drug regime was achieving an 80% cure rate after six months for under $100, compared to the previous 50% rate after 18 months for $2,000.