I don't know about you, but I'm already eagerly awaiting Paul Thomas Anderson's next film (whatever and whenever it may be).
To tide me over, I started rewatching Punch-Drunk Love (my favorite PTA movie), and ever the trivia junkie, I started looking up some behind-the-scenes info, which snowballed into looking up behind-the-scenes info for all of his films.
Here's some of what I found out:
1. As of early 2022, Anderson has directed nine feature films.

2. Most of Anderson's movies are set in the past.

3. Like Wes Anderson (no relation), Paul Thomas Anderson has collaborated frequently with the same people.

4. Between the two of them, Jon Brion and Jonny Greenwood did the scores for eight of Anderson's nine films.
5. Aimee Mann also performed or contributed music for the first three of Anderson's films.
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She sings "Christmastime" over the Hard Eight credits; the song "Voices Carry" by her former band 'Til Tuesday is briefly heard in Boogie Nights; and she's responsible for a huge chunk of the Magnolia soundtrack.
6. Mark Bridges has served as costume designer on every one of Anderson's movies.

7. All nine of Anderson's movies have been produced by Daniel Lupi, who was also an EP on Us, Her, and Lincoln, to name a few.

8. Lupi's fellow producer JoAnne Sellar has worked on each of Anderson's movies, minus Hard Eight.

9. Casting director Cassandra Kulukundis has also worked on every PTA movie except Hard Eight.

10. Actors Philip Seymour Hoffman, Philip Baker Hall, John C. Reilly, and Melora Walters all starred in Anderson's first three films.
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Hoffman also appeared in Punch-Drunk Love and The Master (alongside Walters), and Reilly was just in Licorice Pizza.
11. Luis Guzmán appeared in Boogie Nights, Magnolia, and Punch-Drunk Love.

12. Philip Seymour Hoffman improvised most of his scenes in Hard Eight.
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In an interview with Rolling Stone following Hoffman's passing, Philip Baker Hall said: "I was shocked at his ability to improvise his way through. He improvised most of that craps scene and just had such a sense for timing. At that point, I was older, and he was very young. I was like, 'Who is this kid?'"
13. Burt Reynolds turned down the role of Jack Horner in Boogie Nights seven times.

14. In fact, Reynolds hated the film so much he fired his agent after seeing it for the first time.

15. William H. Macy didn't need to audition to play Little Bill.

16. Actual adult film stars appear in small roles throughout Boogie Nights.

17. Mark Wahlberg kept the prosthetic penis he wore to play Eddie.

18. Tom Cruise was such a fan of Boogie Nights he specifically asked Anderson to cast him in his next movie.

19. Anderson was inspired by Aimee Mann's music to write Magnolia.

20. Mann's music is also literally seen in the movie.

21. If you think Magnolia is too long, you're not alone.

22. Pat Healy plays two separate pharmacists in Magnolia.
23. Thomas Jane was also supposed to play two roles, but due to scheduling issues only appeared as a young Jimmy Gator.

24. Anderson wrote Punch-Drunk Love with Adam Sandler in mind.

25. After seeing Magnolia, Sandler wasn't sure if he could actually work with Anderson.

26. Sandler wasn't the only one doubtful about his casting.

27. In Punch-Drunk Love, the first time Barry goes to the grocery store, an out-of-focus character in red clothes is seen following him.

28. The cuts on Barry's knuckles after he punches his office wall spell out "love."

29. According to Jon Brion, Anderson wanted Punch-Drunk Love "to feel like a musical but nobody ever breaks into song."
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30. The song "He Needs Me," heard when Barry and Lena meet in Hawaii, is originally from the 1980 live-action adaptation of Popeye.
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Shelley Duvall sings it as Olive Oyl.
31. There Will Be Blood star Daniel Day-Lewis was a fan of Punch-Drunk Love.

32. Day-Lewis listened to oral histories from the turn of the 20th century to nail down Plainview's voice.

33. Day-Lewis' speech about building schools and bringing bread to Little Boston was improvised.
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34. Paul Dano originally was only supposed to play Paul Sunday.

35. The story about O'Neill's departure changes depending on who you ask.

36. The film The Master was partially inspired by L. Ron Hubbard and the Church of Scientology.

37. Joaquin Phoenix's parents were briefly members of the Children of God cult.

38. Freddie's first lines in The Master — and the opening lines of the whole movie — were improvised by Phoenix.
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39. Inherent Vice was Anderson's second time adapting a novel.

40. Inherent Vice is also the first film adaptation of one of Thomas Pynchon's novels.

41. For a while, Robert Downey Jr. was attached to play Doc.

42. Inherent Vice originally didn't have a narrator.

43. Inherent Vice was the first of Anderson's films that Maya Rudolph, his wife since 2001, appeared in.

44. Rudolph inspired Phantom Thread.

45. Daniel Day-Lewis once again employed his meticulous method acting to play Reynolds Woodcock in Phantom Thread.

46. According to Day-Lewis, Phantom Thread is his final film.

47. Anderson specifically didn't want Phantom Thread to look like a certain Netflix series.

48. Jonny Greenwood earned his first Oscar nomination for the Phantom Thread score.

49. The term "licorice pizza" is slang for LP vinyl records.

50. Anderson wrote the role of Alana Kane in Licorice Pizza specifically with Alana Haim in mind after directing music videos for her and her sisters.

51. Philip Seymour Hoffman's son Cooper was cast after Anderson had trouble finding a trained actor who could match Haim's energy.

52. Haim and Hoffman had met years before starring opposite each other.

53. The character Alana's family is played by the real-life Alana's family.
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Her mother Donna was Anderson's art teacher in elementary school.