Meaning of "Thank you very much" after a declarative sentence

[Mohammad.Moab]

I started reading Harry Potter's novel yesterday. The first sentence of this book is:

Mr. and Mrs. Dursley, of number four, Privet Drive, were proud to say that they were perfectly normal, thank you very much. They were the last people you’d expect to be involved in anything strange or mysterious, because they just didn’t hold with such nonsense.

I can't understand the meaning of "thank you very much" in this paragraph. The author doesn't talk to anybody in that. why she should say thank you very much?

 

[Rover_KE]

It reaffirms that they're proud to be perfectly normal.

 

[Mohammad.Moab]

It reaffirms that they're proud to be perfectly normal.

Could you elaborate more?
How does it reaffirms that they're proud? Can you give me another example about this?

 

[Charlie Bernstein]

Could you elaborate more?
How does it [STRIKE]reaffirms[/STRIKE] reaffirm that they're proud? Can you give me another example [STRIKE]about this[/STRIKE]?

It is a common expression. It is NOT to be understood literally. It expresses finality, like a door slamming shut.

It means something like:

- Don't you dare think they're not normal!

- They'll thank you not to discuss it further. There's absolutely nothing to discuss. They're normal, full stop.

- There's simply no question. They are very normal.​

The book is written in the voice of a certain educated British class. The language is playful and entertaining for readers who recognize the voice, but it can be hard for others.

So hang in there! We can help you get through it.

 

[tedmc]

I think "thank you very much" was said with a hint of cynicism, meant to be a response to people who seemed to be unduly concerned about the couple's well-being.

 

[TheParser]

Can you give me another example about this?

NOT A TEACHER

Mohammad.Moab, I think that your question is very important for learners to understand. Sometimes, of course, "Thank you very much" means exactly that: "I thank you very much for what you have just done."

Sometimes, it can have a different meaning depending on the situation. I made up this dialog(ue).

Tom: I see that you are trying to climb up a ladder to change a burned-out lightbulb. Can I help you?

Joe: Help me? I am still capable of doing it myself, thank you very much! (Joe feels insulted by Tom's offer. He may feel that Tom is implying that Joe is too old or too weak to do the work without assistance. In a sense, it is a nice way to say "Mind your own business!")