The awkward meeting with the eccentric parents (David Thewlis and Toni Collette) who seem to be growing old and young as the night progresses, lending more to Jake's inner life.
It seems pretty clear that Lucy and Jake are the same person and Lucy, however three dimensional she is, is a fantasy character of Jake, who himself might or might not be an old janitor at a high school which he was once a student of. Lucy is smart, assertive in her thoughts, a multi-talented brainiac who is pretty enough but not pretty-pretty - those girls in his high school who shunned him and bullied him.
With talking animated pigs, dance sequences and Oklahoma!, I'm Thinking of Ending Things is filled with idiosyncratic moments very much like Kaufman's other films. But they can't overcome the film's overwhelming sense of existential dread. Kaufman's neuroses are in full display from traumatized, friendless high school years, consuming books and movies and becoming a reference of a person. Even Lucy, however quirky dreamgirl she is, is just a composite of whatever he got from books and painting and movies. It's a pity that we only see Lucy in the confined space the whole time. I do like Jessie Buckly the actress a lot. But she has given very little to express herself, unlike, say Clamentine from Kaufman scripted Eternal Sunshine of the Spotless Mind.
Jake is a frustrated, extremely insecure man. Even his fantasy is considering dumping him. He sees all the niceties and family life lies. As he accepts a Nobel Prize, and give a speech from some cheesy Hollywood movies and sing a song from Oklahoma! on stage in front of his family and friends who are wearing heavy makeup, I'm Thinking of Ending Things is not Fellini's 8 1/2. It's not celebration of life. Life is a fast train to hell. I mean heck.