@Flowers: yeah, I've heard of professional wine tasters being tricked like that. I think a lot of it has to do with that idea of people assuming cost=quality like I said. The people that are trying to trick them are like "haha, this dummy likes the $8 bottle more than the $50 bottle. What a fraud" even though sometimes the $8 bottle really is better than the $50 bottle. When they switch the labels, the wine taster picks based on the reputation and cost of the mislabelled brand and it seems natural that their opinion of its taste would be affected by their preconceived notions. That's human nature.
Like you said though, even you would probably be able to pick out which wine is better than the other but if you were told beforehand that one is top of the line and highly rated and the other is ghetto wine, your mind might trick you into thinking the former tastes better even if it's actually worse. (Also, what with taste being subjective, the wine you like better might be considered shitty by most wine tasters - but that wouldn't make you objectively wrong.)
On Penn & Teller's show, Bullshit!, (a GREAT show about skepticism that covers a huge range of things - not just the obvious stuff like mediums and psychics - and should be required viewing for everyone in the world. Seriously, watch it. It owns.) they pulled this with bottled water at a nice restaurant. They gave people different waters from faucets and hoses and told them it was super fancy and expensive water from various exotic locales. In some cases, they gave people the same exact water twice in a row but pointed out different supposed qualities each glass had and the people drinking it convinced themselves that they could tell the difference between them. And, of course, they rated the supposedly most expensive waters the highest.
This doesn't mean that every type of water tastes exactly the same though (like, Evian tastes really unsmooth and cheap to me despite its cost and the tap water at my grandmother's house is way better), it just means that people are very impressionable. This is why marketing works.
Another example: Absolut vodka is very well-marketed (I'm sure even the non-drinkers here have heard of it) and it's priced as a mid-topshelf vodka, so people who don't know anything about vodka buy it because of brand recognition and because they assume it's good since it's somewhat expensive. In reality, it's shittier than Popov, which costs at least half as much. It's not smooth at all (which is the number one quality one looks for in a vodka) and it tastes like rubbing alcohol. Still, it's probably the number one brand.
@Berserk: the above applies to what you said too. Exoticism is definitely a factor like cost (again - it's a matter of marketing). I'm pretty sure you can get tea that's just as good if not better here in the US than anything from India or wherever and I'm sure your homemade tea was just fine. I was just trying to say that there's a huge difference between, like, Earl Grey and chamomile and most people could tell the difference. People who have tried tons of teas and know a lot about them could differentiate between teas even further, picking up on subtle differences between two Earl Greys and two chamomiles that may not be apparent to someone less familiar with the beverage. The more you drink it, the less it all just tastes like the weeds from your yard.
It's sort of like how people who aren't that familiar with a certain genre of music (I hear this about metal a lot) will claim that it all sounds the same while that seems crazy to someone who is well-versed in that genre and can effortlessly classify bands into dozens of sub-genres.
Sorry this was so long.
I do know about Japanese valentine's day, and have been making it a point the past couple days to playfully complain, where appropriate, that the boys should prove chivalry isn't dead and give the ladies chocolates like they're supposed to. 
To which all my female coworkers have been replying, "No, I think chivalry is dead in Japan!" and the guys just sort of mentally crawl into a corner and look for an escape route without saying anything, hahaha. Yeah, I'm not giving chocolates to the guys on valentine's day- that's just a world gone topsy-turvy. 
