Good question! "The term originated from the word 'peeve', and is relatively recent - its first usage was in 1919. The term is a back-formation from the 14th-century word 'peevish,' meaning ornery or ill-tempered." http://en.wikipedia.org/wiki/Pet_peeve#Origin A "peeve" is something that annoys or irritates you, and since irritation is a highly individual emotion, one's "peeve" mileage may vary from one's neighbor's. I am "peeved," for instance, by people who assume that my license plates (which refer rather cryptically to books) mean that I spend every waking hour rooting for the Ohio State Buckeyes. Buckophiles, conversely, are probably peeved at the cool disdain with which I disclaim any pro-Buckeye sentiments. For a word that expresses a universal (one presumes) human emotion, "peeve" is a remarkably recent coinage, first appearing in print as a verb only in 1908 and a noun (the thing that peeves) in 1911. Both "peeves," however, arose as what linguists call "back-formations" of the much older term "peevish," meaning "ill-tempered," that first appeared in the late 14th century. Back-formations, the derivation of a "root" word from a more complex form, are common in English -- the verb "to sculpt," for instance, was formed from the much older word "sculptor." "The precise derivation of "peevish" is uncertain, but it may be related to the Latin "perversus," meaning "reversed, perverse." The original meaning of "peevish" was simply "silly or foolish," but by about 1530 it had acquired the sense of "irritable, ill-tempered or fretful." Surprisingly, it then took several hundred years to develop "peeve" as the word for the irritating agent or action. "Pet peeve," meaning the one thing that annoys you more than anything else, first appeared around 1919. The "pet" (in the sense of "favorite") formulation probably owes its popularity and longevity to its mild perversity ("favorite annoyance" is a bit oxymoronic) as well as its snappy alliteration." http://www.word-detective.com/060704.html