Grey's Anatomy, Season 6

Meredith:
[voiceover] Surgeons are detail-oriented. We like statistics and checklists and operating procedures. Our patients live because we enjoy following the steps but as much as we love to always rely on the numbers, the plan we also know that some of the greatest medical discoveries have happened by accident. Mold: Penicilin. Poisonous tree bark: a cure for Malaria, a little blue pill for high blood pressure, impotence be damned. It's hard for us to accept that it's not always the hard work or attention to detail that will get us the answers we're looking for. But sometimes we just have to sit back, relax and wait for happy accident.