If you would stop to think for a moment, you'd realize that how inappropriate it is for one such as yourself to address as William someone such as my father.
13 seconds sound clip from the The Remains of the Day movie soundboard.
You can hear this line at 00:15:53 in the Blu-ray version of the movie.
Quote context
[...]
- True.
- I don't quite understand what you're getting at, Mr. Stevens.
- I am the housekeeper in this house, and your father is the under-butler.
- In other houses, I was accustomed to address under-servants by their Christian names.
- I might point out that you're still often unsure of what goes where and which item is which.
- I'm sure Mr. Stevens Sr. is very good at his job, but I can assure you that I'm very good at mine.
[...]