Grey's Anatomy, Season 15

Meredith (voice over):
There is a reason so many babies' first word is "NO". It's because it's the word they hear the most. From the second we are born, we want to cross the line, push the boundaries, test the limits. But then we grow up and learn that not all rules are bad. Some boundaries protect us, some lines keep us safe. But the nice thing is that we can choose for ourselves - we can screw the rules or we can make our own.