This old fashioned greeting came to mind, and I realized that I didn’t know what it meant. Is it basically saying, I’m sure I’ll be charmed by you as we get to know each other? Or is it something else?
“I’m sure I’m already charmed. Even though we’ve only just met and all I know about you is your name, your radiant charm is so immediately obvious and so compelling that I can be in no doubt of it. I am being washed away by the tidal wave of your charm.”
It’s the same thing as saying “Nice to meet you” before you know whether it will turn out to be nice at all.
Does anyone still say “How do you do?” when they are introduced to someone? I’m watching an episode of Poirot, and everyone says it.
“How do you do” was already well on the way to extinction by 1972, when it spawned some of the worst lyrics in pop music history.
How do you do, ooh-hoo
I thought, why not, na-na, na-na
Just me and you
And then we can na-na, na-na
Just like before
And you will say na-na, na-na
Please give me more
And you will think na-na, na-na
Hey, that’s what I’m livin’ for
It’s formal politeness connoting “it goes without saying,” “no need for further evidence,” “you may be the devil incarnate but we’re all gentlefolk here.”
As an affirmative meaning “yes, certainly” it dates from 1803, from Middle English meanings “firmly established; having no doubt,”
“How’s it hanging?” has always had some dodgy connotations for me. 
“How are you today?” seems to be the standard English greeting now. Standard enough that it is the first line on every Indian call center’s script. Wouldn’t it be strange to get a scam call that began, “Are you charmed today?”
It expresses confidence that, should I actually get to know you at all, I’m sure I will be totally charmed by you.
“Your servant” from the 18th-19th century always struck me as odd. Why would I suggest to the person I’m meeting that I’m now their servant?
In the same way, an official from a hundred-plus years ago might end a letter with the words: “I am (remain) your humble and obedient servant”. They meant nothing of the sort of course. In fact - the total opposite.
It’s official. Americans no longer even have the concept of manners and etiquette.
I’m torn on whether this is a good thing or not. Manners are nice; etiquette is not.
WTH, are some kids on your lawn or something? Some old time greetings sound odd, and we no longer have the concept of manners because we’re asking about it?
There are certain phrases or sentences in the languages that perform social functions and are not to be taken literally.
For instance, when someone says, “How are you?” they don’t expect a long discussion of your health and may be embarrassed if you go into one. The correct reply would be “good” or “fine” or the equivalent, with you adding another “How are you?” which also gets no meaningful reply.
Another example is “Thank you.” You’re expected to say “You’re welcome” or some standard acknowledgement. It seems that “No problem” is becoming common right now, creating indignation among some old farts. The heart of that is that the reply is not part of the social script.*
So “Charmed, I’m sure” was, at some point in time, the correct answer to an introduction. Nowadays, it’s more likely to be “Good meeting you,” and in the past, the phrases “How do you do?” and “Glad to know you” were common.
The phrases often change over time, but the point of them is to use a standard phrase that makes an acknowledgement of the situation. Using a different phrase can be seen as mildly hostile.
*I have no problem with it.
Or…
My name is Sue, ♫
How do you do?"
I like this explanation. A similar use is “I’m sure I don’t know”. In both cases, the speaker is declaring their own internal experience, a declaration they are uniquely qualified to make. So, “sure” always sounded redundant to me – how could a person not know whether they themselves are charmed, or whether they know. But by this definition it also works in the sense of emphasizing. Oh, yes, I’m absolutely charmed! I absolutely don’t know!
I think it’s a bit more nuanced than that. If I ask my neighbor to do something for me like lend me his lawn mower, then “no problem” is more correct than ‘you’re welcome’. If I say ‘thank you’ to a cashier, then a ‘no problem’ response seems awkward. Of course there’s no problem, they’re doing their job. I haven’t potentially caused them a problem.
Am I misremembering or did Jennifer Coolidge use this phrase in Best in Show?
I’ve always read this as sarcastic. As if the speaker is distancing himself from the actual statement by referring to it with a level of remove.
This is fine. → normal
I’m sure this is fine. → sarcastic
It depends on how it’s said though.
“I’m suuuure this is fine.” With an eye-roll, and then a sigh afterward.
“I’m sure this is fine.” Spoken gently while patting someone’s shoulder.
The first one is clear sarcasm, the second one is sincere and meant to reassure someone.
As far as confusing greetings, when I was a kid (we’re talking elementary school age) people used to ask me, “What’s up?” And I’d respond, “The sky.” Partially because I was a little smart-ass, and partially because I didn’t really know how to respond. I never took it as a greeting that you didn’t need to actually answer, that didn’t dawn on me until I got older and matured a lot more socially.
That’s true. It’s possible that my perception is being biased by the phrase being cliche enough to be now used more sarcastically. I can’t specifically name any movies, but I’m certain I’ve seen a few where a man encounters an unpleasant woman in a social situation and says “charmed, I’m sure” dripping with sarcasm.