The name was famously borne by the narrator of Laurence Sterne's classic digressive comic novel _Tristram Shandy_. Tristram's father Walter Shandy, who believed that a man's destiny was determined by the length of his nose and nobility of his name, wanted to give his son an especially ennobling name to counter the damage done when his nose was accidentally cut short at birth. Walter chose to call him Trismegistus after the Greek form of the Egyptian god Thoth, but Parson Yorick did not recognise this name and Tristram was christened with what happened to be Walter's least-favourite name.
In an allusion to the info in the first posting, Anthony Burgess ("A Clockwork Orange") names his most rational-yet-victim-of-fate-character in his novel "The Wanting Seed" Tristram.