While listening to Mark Chrislip's excellent QuackCast podcast on herbal remedies (episode 13), I recalled that I used to also drink copious quantities of Smart(fx).
From the Wiki:
Smart(fx) is a brand of alternative beverage that originated in Toronto, Canada, in 1996. The various flavours of this beverage are made with juices and herbal extracts and contain no artificial flavours or added sugar. They are kosher and GMO-free and come in four flavours: Original, Cranberry, Raspberry-Green Tea, and Blueberry Hemp.
I used to pound back one of those babies before every high school exam. Just in case.
The "original" flavour (my favourite, although the cranberry variety was good too) tasted vaguely like orange juice mixed with licorice, and was an acquired taste. It seems that the drink has been unavailable for some time. (And, probably as a result, links to the official Smart(fx) website result in the message "Account for domain naturaldrink.com has been suspended".) If I recall correctly, it was a cocktail of fruit juices, Ginkgo biloba, Paullinia cupana (guarana), and Panax ginseng (although I'm sure that there were probably other "medicinal" ingredients).
Presumably, had I drunk more of it I would have remembered using it sooner, as it claimed to improve memory and implied (at the very least) other cognitive benefits. In fact, I was briefly concerned over the ethics of using this "performance enhancing drug" to ace my exams.
I wonder what other crazy things I used to believe.