"The More You Know"[1] is a series of public service announcements that has been running on NBC Universal programming in the United States since September 1989. Each clip typically begin with an educational message from a celebrity and conclude with an animated sequence of a comet trail created by Paul Johnson. Being one of the longest-running network public service campaigns to date, the PSA series has been widely parodied both online and in popular culture.
Mnemonics are useful for remembering stuff. (Shocking revelation, I know.) I barely know anything about history for example. But I remember "333 - Issos Keilerei", rhymes on German and means "333 - Issos Brawl". I didn't even remember what this was about until I looked it up just now on Wikipedia.
The Battle of Issus (also Issos) occurred in southern Anatolia, on 5 November 333 BC between the Hellenic League led by Alexander the Great and the Achaemenid Empire, led by Darius III. https://en.wikipedia.org/wiki/Battle_of_Issus
But hey, I remembered this. My history teacher back in school did something right.
No, I don't think it was or is particularly useful, besides things like "brain fitness". It might have helped me back then to get a better grade, though. (Yes, we see now again how useless it is in many cases to memorize stuff for school/uni/whatever.)