Useful

History

The original use of Useful as a term came from the mind-controlling weasel character Corasyn on Puzzlebox (see alt User:Trouffee for more details). Useful at that time was defined as "the least intrusive method by which to control someone's mind." The fact that an action or object was Useful meant that it was pleasant to do without forcing a person to perform said action or with said object.

The more modern usage came from an introductory hypnotic session between User:Trouffee and Kincaid, in which the term repetition is useful was itself used several times to explain what a hypnotic trigger was and the best method to implant such a trigger. After that session, Kincaid could not help but finish the stated sentence "repetition is" with the callback "useful." The term later expanded to include any "x is useful" sentence and spread as a meme/hypnotic trigger among many Postfurries.