According to my German professor in college, the irony of Americans using Gesundheit is that Germans say zum Wohl, “to your health.” Maybe your guy was German and trying to figure out if you were putting him on.
Jesus! I’ve been screaming Schweinhunt! all these years when people sneeze. My Hollywood German lets me down again.
Well, did you ever see some people sneeze? Saying Schweinhunt might be appropriate. I know it is for about 1/3 of my cow-orkers.
Guess it depends on where you live in Germany. In Hochdeutsch, using gesundheit is rather common.
Given the usage of the term in the media, perhaps the person in the OP belongs to a sect that doesn’t watch TV.
Native Southerner (South Carolinian) here. We hear “gesundheit” all the time. “Bless you” is probably more common, but gesundheit is not what I would call rare.
RR
No, Grandma Renee specifically said to leave out the first “e” when typing it out. 'Didn’t make any sense then, and it sure doesn’t now, but that’s what she put in the wax-sealed manual she left in her will. Even had it underlined and highlighted.
(That is to say, I made a one-letter typo) 
Google reported this as a hazardous site. Just FYI for others.
It is common for me, but then I grew up in eastern PA, so I guess I haven’t expanded the sample-set much.
I’ve lived in Northern IL (McHenry County) for my entire life. I am part German (1/4), and have heard gesundheit used all the time by a great many people.
Now, it’s possible that since I live near the Wisconsin border and there is a heavy German influence around here that it is more commonplace, but I really thought it was a common knowledge thing.
I always thought it was more fun to say than “bless you”, but once I got out of religion, I really didn’t like saying the other phrases, though I am not bothered by others saying it to me.
In a Food channel feature on wines from South Africa, the cheerful vintner was asked what South Africans say to make a toast. “Gesundheit,” he said, "which means ‘to your health.’ "
The whole “saying something after a sneeze” ritual is said to be based on superstition about demons. I’ll say gesundheit for a sneeze, but to mock the custom, I also gesundheit belches and farts.
Chicago. “Bless you” is most common, but “gensundheit” is pretty universally understood, although I’ve heard the pronunciation more as “guh-ZOO-tight.”
I’ve been known to say “Jupiter preserve thee”, which is what my high school Latin teacher claimed was what the Romans said after someone sneezed. Definitely gets me some interesting looks when I do it.
Cheers,
bcg
I have an annoying dislike of conditioned-response phrases (For instance, I often will answer truthfully when people ask, “How are you?” which I think most people hate. And yet, they never stop asking!), so with people I know, I sometimes say, “Dia linn!” Which is Irish Gaelic for “God with us,” and is, I’m told, what Irish speakers say when someone sneezes. It’s one of about 4 Irish phrases I know.
With people I don’t know, I’ll usually use “Gesundheit.”
I’ve been out of German for a bit, but I thought heit/keit were endings like the English “ness”. Meaning it would mean more like “health(ful)ness” (which I admit with “-ness” is a bit redundant since its function is to make the word a noun, but IMO does make the function a little more clear) or perhaps better (if a bit less literal) “[may you] have health.”
Of course, chances are I’m totally off.
FWIW, if you pass “gesundheit” to the Babelfish translator (http://babelfish.yahoo.com/) and choose “German to English”, the translator returns “health” as the English translation. Babelfish translates “gesund” as “healthy”, so literally reading “-heit” as “-ness” that gives you “healthyness”–for which “health” would be more idiomatic English.
Basically, I think you’re right on the meaning of “-heit”/“-keit” (based on what I remember of my college German), but that doesn’t mean that such constructions have a one to one correspondence with English constructions which use the “-ness” suffix.
Cheers,
bcg
You’re right about the suffix, but the difference is, in English, there’s the noun “health” onto which you add a suffix to get the adjective “healthy”. In German it’s the other way around. There’s the adjective “gesund” onto which you add a suffix to get the noun “gesundheit”.
In other words, what Bluffcityguy said.
I believe keit would be “ness” (similar to kronkite = sickness). Heit is more like “ly”. Gesundheit means “healthily”, or “with health”.
Nearly on topic: I was on a train in Belgium talking to an Irish guy (in English) while two comely lasses of the Germanic type (I wasn’t going to try to spell “Fraulein”) were talking in German and glancing at us and all that girly stuff. We knew basically that they were talking about us. Then one sneezed. I said “Gesundheit!” and she turned beet red and gasped, “Sprechen ze Deutch?” (I know I mangled that), to which I replied “Enough to get by.”
In truth my German comes from watching Hogan’s Heroes.
Atheists avoid even saying those words? News to me! (Sorry for the hijack.) I couldn’t get through a day without “Oh for God’s sake” as a replacement for a far more inappropriate comment!