“Most English-speaking people,” the fantasist and philologist J. R. R. Tolkien wrote, “will admit that cellar door is ‘beautiful’ . . . More beautiful than, say, sky , and far more beautiful than beautiful .” This comeliness is partially attributable to the psychological phenomenon called semantic satiation, in which the repetition of a word or phrase causes it to lose, or somehow transcend, its meaning. It is experience that defines the most memorable sequence in the HBO comedy The Comeback , which first aired on HBO in 2005 and is returning after a twelve year-absence for a third and final season. Late in the series’ pilot, washed-up sitcom starlet Valerie Cherish (Lisa Kudrow) is running some lines for her new role on a broad, hacky sitcom called Room and Bored , in which she has been cast as fussy landlady Aunt Sassy. Desperate to revive her flagging career, she spends hours repeating her one, unfunny line, over and over.…