Its from a Seinfeld episode. "this" means friendship, "that" means sex/kino....everyone says something different for "other". Some say its "security/comfort", others say "commitment"...seems to me people are fooling themselves, and there is no "other", commitment is a logistical thing, possible useful/nessessary, but not a thing in itself to be valued , as with "this" and "that"...feelings?