"The toothache" vs "A toothache"

[Tom]

Hi

Please see below:

Detective: Where were you last night at 10?
Man: Sir, I had the toothache, so I went to bed early.

Why the toothache, why not a toothache?

Tom

[Yankee]

Hi Tom

To me it sounds like the man had already mentioned his toothache to the detective previously. So, he says the because he is referring a specific, previously mentioned toothache.

Amy

[Tom]

I may assure you, Amy, he had not. It was the first time he was meeting Hercule Poirot in Murder on the Orient Express

Tom

[Yankee]

.
Well, Tom, I guess you'll have to ask Agatha what she had in mind.
.

[Tom]

[Conchita]

Perhaps the word ‘toothache’ was used as a generic noun? Like when you say ‘the flu, the measles’ (or ‘the blues!), for example.

http://www.artoftheprint.com/artistpages/rowlandson_thomas_tooth_ache.htm

We’ve come a long way. Or have we?

Don’t miss the resourceful chap’s inexhaustible list of professional services (factotum indeed!) – incongruous, to say the least (at least by modern standards). By the way, has anyone got a clue as to what is meant by ‘Wash Balls’?

Oh, and one last question: how could people in those days happily buy black pudding from someone who bleeded people?

I know it’s supposed to be a satirical description, but all the same!

[Yankee]