Freud's first line, bewildered by the phone booth's presence: "This is a dream?" Dream interpretation is a key tool in psychoanalysis, which Freud created.
Joan sees the phone booth appear in front of an altar while she's praying. She probably thought Bill and Ted were angels there to take her to heaven. Note that the real Joan of Arc claimed to have talked to angels.
Lincoln acts surprised when the camera flashes as he's getting a portrait. In Lincoln's time, photography required a long period of calibration and the subject standing perfectly still. He no doubt was startled that the picture was taken instantly.
Billy's casual demeanor and smirk when he is being interviewed by the San Dimas Police. He'd been to jail a few times at this point in his life, and escaped every time. Surely he's confident he could do it again.
Napoleon gets into "Waterloo" (a stealth pun on its own) because he walks through the turnstile in the middle of a group of kids. Napoleon has a famous (though untrue) reputation for being short.
Socrates is understandably astonished at the first few stops he makes with the group, but none more so than the brief trip to the future... where they arrive in a palace-like structure with metallic walls and a group of robed figures seated on floating thrones. He must have thought they had traveled to the abode of the gods on Mount Olympus!
After misidentifying Joan of Arc as "Noah's wife", Bill and Ted wonder aloud "Then who was Noah's wife?" This is actually a very good question in itself, because (like many Biblical wives) she is nameless in the text, having few identifiable qualities beyond being the wife of Noah.
The movie lampshades the illogical nature of time-paradox causality loop from the start:
Bill: Wyld Stallyns will never be a super-band until we get Eddie Van Halen on guitar. Ted: Yes, Bill, but... I do not believe we will get Eddie Van Halen before we have a triumphant video. Bill: Ted, it's pointless to have a triumphant video before we have decent instruments. Ted: Well, how can we have decent instruments if we don't really even know how to play? Bill: That is why we need Eddie Van Halen! Ted: And that is why we need a triumphant video! Both:[think for a second] EXCELLENT! (guitar riff)
This dialogue parallels the inherent problem in the time-loop:
To do their history report, Rufus had to help them For Rufus to exist, Bill and Ted had to do their history report Bill and Ted did their history report and Rufus helped them with their history report
Joan of Arc being picked up by Bill & Ted can either be considered Fridge Brilliance or Fridge Horror when looked at from her perspective. There she is, kneeling down in cathedral praying for guidance - then all of a sudden thunder and lightning appear above her head and with a bright light a clear glass confessional appears down in front of her with two strange beings offering their hands to take her to a trip to Utopia. There she sees a world where women are treated equally: there is so much peace that women train in regiments for fun: and she gets up on stage and has hundreds of people listen to her without any form of prejudice. Finally she gets sent back and tells everyone her story of meeting an angel and seeing heaven. It's no wonder they thought she was a heretic.
The film begins with Rufus explaining how utopian the future is, but he talks about how "bowling averages are way up, mini-golf scores are way down," and Earth has the best waterslides in the galaxy. It seems merely humorous that he would touch on such trivialities, but perhaps this shows that in Rufus's time, peace and prosperity have been known to the people for so long that they don't even care to mention it if someone asked what makes Earth good. Rufus rattles off hobbies and pastimes because life is just so good that it doesn't even need to be mentioned that there is no more war or environmental concern or other things more pressing to modern people.
Why was the stage set-up and prepared with every prop they needed for their presentation? They engaged in Retroactive Preparation for anything they needed. That's where Gengis Khan got his pole-axe from. They made notes of what they needed and bam! it was there.
Napoleon is shown devouring a gigantic ice cream sundae (and unwilling to share). While ice cream was not widely known (or available) in the early 19th century, the real Napoleon was known to be very fond of it.
Some have wondered why Beethoven is playing a Mozart song during the mall scene (the song played during the scene, "Play With Me" by Extreme, samples part of Mozart's Piano Sonata No. 11). Aside from the awesome factor of the song, remember that young Beethoven was a huge admirer of Mozart and initially traveled to Austria intending to study under him.
Joan of Arc, Abraham Lincoln, Billy the Kid, and Socrates were all executed or murdered, yet Bill and Ted happily send them back to their own time in the end. One wonders whether the boys did enough studying to even find out about the grim fates awaiting many of their new friends.
In particular, Billy and Joan are very close to the age of their deaths: both of them probably have barely more than a few months to live, if that.
