In no strip did Calvin ever say "God put me on this earth to accomplish a certain number of things. Right now I am so far behind that I will never die."
There is a fake strip◊ going around that has fooled a lot of people despite the font looking nothing like Watterson's handwriting, involving Calvin going on meds and Hobbes becoming just a stuffed tiger as a result.
There actually is a band called Le Scrambled Debutante. They're kinda... out there.
The strip in which Calvin provides: "Yakka foob mog. Grug pubbawup zink wattoom gazork. Chumble spuzz." as Newton's First Law "in his own words" inspired a comic book called Chumble Spuzz, by the artist of Axe Cop.
A decade after the series where Calvin and Hobbes traveled to Mars, NASA landed the Pathfinder probe on Mars. Scientists gave nicknames to the various rocks in the pictures that were sent back. Two of the rocks were called "Calvin" and "Hobbes."
Doing It for the Art: Watterson was notorious for resisting every attempt to have his creations merchandised. This has had a two-edged effect on fans, depriving them of many bits of memorabilia that they'd love to have but at the same time preventing possible commercial oversaturation that has happened to other famous comic strips. He also got into trouble with newspapers and syndicates for his strips, in particular his new Sunday strip layout. Usually, Sunday strips are 3 rows of panels. The first row contains the title, and usually a little panel that either contributes nothing or has its own "throwaway gag" that most newspapers remove, leaving the second two rows. He felt very constrained, and so he made use of the entire space with wild layouts of panels going all over the place, even having the entire thing be one panel, just so they'll be forced to run the whole strip.
Fanwork Ban: Watterson has been quite clear: NoCalvin and Hobbes merchandise, of any kind, EVER!
Infamously, neither he nor the syndicate have cracked down on the ubiquitous, unauthorized Calvin-peeing-on-things stickers in any effective way.
Hoist by His Own Petard: Watterson expressed some regret at insisting he get to lay out Sunday strips however he pleased, remarking that it became a lot harder to come up with ideas that didn't flow linearly and organizing images in a way that made sense while not reverting to the syndicate-standard layouts.
Keep Circulating the Tapes: Since Attack of the Deranged Mutant Killer Monster Snow Goons (the last strip compilation in the original "square" format) was never reprinted in a treasury, this was the only way to see the color versions of the Sunday strips between July 8, 1990 and April 10, 1991 until the release of the complete anthology.
A strip from November 28, 1985◊, involving Calvin trying to bathe in a washing machine, only appeared in a few papers. It did not show up in any of the anthologies, which had an alternate strip (Calvin saying dinner tastes like bat barf, being told to go to his room, then ordering a pizza.)
The original version of the August 28, 1988 strip was unprinted for many years, as the books used a specially redrawn version to fit the template of the books at the time. The original was eventually published in the Sunday Pages catalog.
Before adapting the character into one of Calvin's alter egos, Bill Watterson tried to produce a comic strip starring Spaceman Spiff. In this early version, Spiff was a cigar-smoking astronaut with a Chaplin moustache. He had a dimwitted assistant named Fargle, and they flew through space in a zeppelin. For obvious reasons, as Watterson notes in the Tenth Anniversary Book, the syndicates rejected it.
Watterson regrets introducing Calvin's uncle Max, who appeared in only one short storyline before being subsequently put back on a plane forever.
Reality Subtext: Countless strips, were based on exchanges between Watterson and his syndicate. Notable examples include the Neo-Cubist and black-and-white Sunday strips, where the Art Shift was a metaphor for the two sides of the debates.
Reclusive Artist: Watterson always valued his privacy and rarely gave interviews when Calvin and Hobbes was running and would not allow journalists to take his photo note the one photo of him that is circulating is decades old or record his voice. He's spoken to exactly one journalist since the strip ended, in a short interview on Watterson's doorstep after the journalist was able to track him down and badgered him for the opportunity. People's speculation about his reclusiveness may have been blown out of proportion, however. He now paints landscapes and lives in suburban Cleveland and locals say that he is out and about and occasionally sneaks autographed copies of Calvin and Hobbes collections onto the local bookstore's shelves for fans to find, giving the impression of someone who simply prefers keeping to himself rather than shutting out the world altogether.
The only piece of art that he has released since ending the strip was an oil painting sold to charity in 2011, and he's only heard from every 2 or 3 years, whenever he writes a very brief review of a book or gives a very brief interview. His audio-only appearance in the 2014 documentary Stripped (which he also drew the poster for) marked the first time his voice had ever been publicly recorded!
During his political cartooning years, he did the same, as well as skipping award presentations in his honor and ignoring the demands of his superiors, no matter how minor. This reclusive nature seems to point to a personal issue with people rather than concern for the well-being of his craft.
He resurfaced in June 2014, collaborating with Stephan Pastis of Pearls Before Swine on a short story arc.
The year before that he had produced an oil portrait of Petey Otterloop from Cul de Sac, for which he also has written a compilation foreword.
Screwed by the Network: A variation. Universal Press Syndicate was happy to keep running Calvin And Hobbes, but their inflexibility in accommodating Watterson, especially with alternate strip layouts, was a major contributing factor to his decision to kill the strip.
Short-Lived Big Impact: Only had a run of 10 years, surprisingly short for such a successful comic strip, and absolutely no new strips or supplemental material (barring collections) have been made since — but it has still remained one of the most well-regarded, influential comic strips in the medium's entire history.
Shrug of God: Watterson's been very ambiguous with regards to Hobbes' true nature. He is real to Calvin, and a toy to everyone else, and which view is correct is entirely up to the reader.
Technology Marches On: The arc where Calvin locks Rosalyn out of the house would go a lot quicker if used today largely due to the availability of cell phones. Rosalyn could call Calvin's parents and explain the situation or at the very least threaten to do so if Calvin doesn't let her back inside.
This strip still could work if she left her phone on the table before going outside.
Tribute to Fido: Hobbes was inspired by one of Bill Watterson's cats. He explains in the 10th Anniversary Book:
"Hobbes was very much inspired by one of our cats, a gray tabby named Sprite. Sprite not only provided the long body and facial characteristics for Hobbes, she was also the model for his personality. She was good-natured, intelligent, friendly, and enthusiastic in a sneaking-up-and-pouncing sort of way."
Chocolate-Frosted Sugar Bombs: Calvin's favorite breakfast cereal, of which he proudly eats multiple bowls a day (occasionally with cola instead of milk), even though it makes him hyperactive as a result.
Cool but Stupid: Indirectly, from the line "This is so cool!" "This is so stupid!"
Fuzz Therapy: How Calvin describes the mutual pleasure both he and Hobbes incur when he rubs the tiger's belly after a "rotten day."
Misery Builds Character: Often invoked by Calvin's Dad whenever he forces Calvin (or the family) to do something unpleasant. The line below is said by Calvin himself, parodying his own Dad. His mom nearly dies laughing. Dad scowls in reply, but admits that's pretty good.
"Calvin, go do something you hate! Being miserable builds character!"
Hobbes: Is Amazon Girl's super power the ability to squeeze that figure into that suit?
Calvin: Nah, they can all do that.
Noodle Incident: The mysterious "Noodle Incident." The story is just as fragmented and impenetrable in-universe; not even Santa Claus can piece it together. Calvin himself claims he was framed (on the few occasions he can even think about the event without having a panic attack.) Word of God has said that he never actually went into detail about the Noodle Incident on purpose. Watterson had plans to before he ended the comic, but he then figured that no matter what he came up with, it would never be as hilarious as the many things that the readers could have thought about it.
For the most part, averted, but it does pop up rarely in a few of the '80s strips such as Calvin referencing VCRs and records, commenting on New Wave fashion trends, comparing his dad to Gene Siskel, or a couple of Cold War references. The comic books that Calvin devours are clearly from the Dark Age of the medium's history.
What Could Have Been: Watterson wrestled, for many years, with the idea of creating an animated series of the strip. Although he rejected all other merchandising immediately, he has great respect for animation and considers it to have potential and possibilities that comics simply can't have. In the end, though, he decided against it; he was proud of the strip being his creation alone with no other hands involved, he found it scary to think of his characters being given voices (which would inevitably fail to match the ones in his or his readers' heads,) and he decided that, regardless of animation's possibilities, Calvin was designed to be a comic strip and a comic strip only, and would inevitably lose something if adapted.