I knew an elementary school teacher who thought gravity was caused by the Earth’s spin.
Because the “v” sound followed immediately by the “w” sound (spelled here, as it often is on French, “oi”) is NOT a valid sound sequence for native English words. So, English speakers (unless they’ve learned some French) tend to find it easier to skip the “v”, and some don’t even “hear” (perceive) it.
In this case, the “wahlah” pronunciation has been reinforced by its frequent use by magicians (and parodies of them - Sesame Street comes to mind), so even English speakers who DO speak some French, and so “know better”, will pronounce it this way sometimes.
Someone I know – an educated adult – until recently thought that south was downhill, and north uphill. Perhaps having lived her whole life literally looking at the Hudson River flow by (by chance, really, from two locations quite far apart, in two phases of her life), helped to reinforce her mistake, since the Hudson does happen t flow from north to south.
It’s the freaking territories, man - those things are weird. Also; superstitious avoidance of the number 13 causes people’s brains to short circuit.
Or something - I don’t know; this isn’t actually something I have trouble remembering!
I think that’s nitpicking - and, in any case, I think there were probably enough people born in Upper and Lower Canada who participated in the war to say that Canadians had a role in it. Aren’t you from Kingston - doesn’t half the town have ancestors who did something or other during the war? I know quite a few people who can make that claim, and I don’t think I’d dismiss it just because it was technically a British force. But that is just IMHO.
You make a fair point that it wasn’t really Canadians that burnt the White House (though do we know that none were involved? I guess it’s all about perspective, when it comes to defining or labeling those who led to current Canadians being here.
OK, fair enough. I know there are a ton of phonemes in French that English doesn’t have, and perhaps my bilingualism gets in the way of my trying to understand why words get mangled the way they do - it seems easy to me, even easier than the various ier/é/er sounds, so it really didn’t occur to me that people don’t even perceive the v.
That said, now that you all know…please pronounce the v sound, for the sake of my sanity 
Also; don’t trust magicians.
Huh? I’ve always pronounced it as “Vwah-lah” no problem.
Same here.
I was surprised a few years ago to find out that my mother didn’t know that a werewolf isn’t always a monster. Admittedly, she’s not a horror fan, but I thought it was sort of general knowledge.
Non-monster werewolves are an artefact of the last 20 years or so (basically since the Werewolf RPG). There are probably some other odd exceptions out there (Poul Anderson’s Operation Chaos stories had a heroic werewolf), but in general prior to that if there was a “heroic” werewolf, it was a human struggling against the curse a la Oz in Buffy the Vampire Slayer.
Good on you (and Lumpy)! 
For speakers of any language, some people are just better than others at perceiving, and using, certain sound sequences not native to their language.
Example: There’s a hot sauce called “Sri Racha”. I have no trouble pronouncing the “sr-” sequence (but I do have to pay a bit of extra attention when I pronounce it), whereas my wife tends to alter it to “seer”.
Isn’t that lack of knowledge kind of mitigated against by the fact that werewolves aren’t real, and therefore technically aren’t anything?
You’re right. I have no problem with “sri” either, but I know that a lot of people do.
I guess I’m weird, though. I understand very little Spanish, but give me some text to read aloud and it will sound perfect-- even though I may have no idea what I’m saying.
Marie de France’s Bisclavret was written in the late 12th century. That might count as an “odd exception,” but it shows the concept has been around for some time. It’s probably not something most people have heard of, but it’s pretty well known as far as medieval literature goes.
I think he was just referring to werewolves being in normal human form until the full moon comes up.
In the UK, where you have to admit there are a fair few anglophones, I don’t think I ever heard anyone mispronounce it. It ALWAYS had a “v” at the beginning.
Heh - I tend to use “anglophones” to refer to English-speaking Canadians and Americans (as opposed to francophones - French speaking - or allophones whose primary language is neither English or French). I wasn’t even thinking about the UK when I wrote that! I am very please to hear that you guys are capable of saying voilà with a v sound at the beginning
I hear what you’re saying, but I don’t notice that when people pronounce “reservoir,” where the same sound combination occurs.
The human werewolf goes back (at least) to 1941’s The Wolf Man, so 70 years.
A lot of people have trouble with reservoir, but the most common adaptation I hear is “rez-uh-var”, skipping the “w” entirely.
I worked at Blockbuster when Reservoir Dogs came out on VHS. There was much mangling of the title by customers. 
Interesting point. I think this is because the second “r” in “reservoir” puts your mouth in a position where the “v” is very easy to get to. Indeed, the last “r” in the word also makes things easier, by making it so you don’t have to open your mouth as wide as you do to make the “wah” in “voilá”.
Interestingly enough, I skip over that first “r”, and say “rez-uh-vwahr.” I only pronounce that “r” if I’m carefully enunciating. Now that WhyNot mentions it, I have heard people say something like “rez-uh-vawr.”
I suppose that “voir dire” as another counterexample is probably not going to get much traction.