in 10 years they’ll be beaming shows sirectly into our subconcious minds, complete with product placement and commercial breaks. after a while, our subconcious will be able to switch channels.
Tinfoil hats will protect against this. send me ten dollars and I’ll make one for you, complete and able to fit intop your letterbox.
I don’t think you do (recall correctly, that is). I’m fairly sure that Casablanca was filmed in 4:3.
I think you might be right partly because I think I’ve been called on this one before (which I naturally only remembered after writing the post…I don’t know why I keep remembering it that way).
In my defense I saw this done in college [sub]cough[/sub] years ago (ok, 15 years ago…I not old enough to be willing to hide my age yet). That I saw something that highlighted the differences as I described (two people having a dialouge) I have no doubt about even if I have forgotten what movie it actually was. Citizen Kane maybe? Or maybe I should just stop guessing and leave it that pan-n-scan can really suck for some movies.
El Cid is literally nauseating in pan-n-scan. There was at least one scene with 2 characters on opposite ends of the screen talking and the view just whooshes back and forth. I had to stop watching cause I felt sick.
Whew. 
Most of the example I’ve seen on the internet with regard to why letterbox is better than pan & scan use a conversation as an example. The one I saw was two guys in a Jeep. Another one was two people talking face to face and in the letterboxed version you get most of their heads in the frame. Who ever created the pan & scan version put the camera right in the middle. So now there are two tiny slivers of faces talking to each other. Horrible.
Whack-a-Mole: The horse is well bruised, but please allow me to beat it some more. 
The 4:3-proportioned screen (which is technically called “Academy Ratio”) was the standard for movies up until the 1950’s. Basically, everything was shot and projected in that format, except the odd novelty project here and there. Widescreen (which these days ranges up to, IIRC, 2.35:1, though there were wider) came about as Hollywood tried to compete with what they perceived as the threat of television. In other words, if the movie was made before 1950, you can safely assume it isn’t widescreen. And yes, that even goes for epics like Gone with the Wind.
However, in your defense, it’s worth noting that a number of movie studios, in the 1960s and 70s, made some foolish decisions based on the reasoning above. In particular, when they were re-releasing older movies, they fretted about whether or not the audience would remember the old ratio, and whether they’d feel strange and disoriented about watching a “square” movie after having gotten used to the wider screen. Thus – and this is where cineastes begin to grind their teeth – they sometimes cropped the top and bottom of an existing film in a misguided attempt to simulate a widescreen look. In other words, old-format movies such as GWTW were sent to cinemas in the 60s and 70s (and even into the 80s) with up to a quarter of the picture sliced off. As you can imagine, the result was a lot of people with no heads and no feet, and otherwise ugly, awkward compositions. I’m clenching my jaw just thinking about it.
Anyway, it’s therefore remotely possible that in that side-by-side comparison you describe, you were in fact looking at an older film in a bastardized version. It’s conceivable that, say, Bringing Up Baby, which Howard Hawks shot with his typically medium-close-up loosey-goosey frame, was given the faux-letterbox treatment, and didn’t suffer too obviously. Then this fake widescreen could be panned-n-scanned, which would result in the impossible-to-watch version you saw.
I’m not saying this is definitely what happened, but if you’re absolutely certain it was a much older movie (pre-1950), then this could account for what you saw.