Yes, interfaces aren't just bags of data and methods. They have semantic meaning, too. An Employee, a Gun, and a ClayPot might all have a method named `fire()`,

Yes, interfaces aren't just bags of data and methods. They have semantic meaning, too. An Employee, a Gun, and a ClayPot might all have a method named `fire()`, but they all mean different things. With structural typing, we can load our Employees into a Kiln and give HR a Gun to downsize the company, and nothing will stop us.