* AscendedFanon:
** On [[https://www.youtube.com/watch?v=9RjctxPWya0 March 18, 2012]], he produced the instrumental track of "The Veldt" on his livestream, posting it to [=SoundCloud=]. The next day, he found a vocal track for the song on Twitter, created by up-and-coming producer Chris James. Skeptical at first, he nonetheless listened to it and was so impressed by the track and how James' lyrics completely fit the theme of the song that he [[https://www.youtube.com/watch?v=bFjc1nOHwlc made it the official vocal track]], earning it a place on both ''The Veldt EP'' and ''>album title goes here<''.
** Downplayed with his 2016 release "Snowcone". After releasing the track, a Toronto-based rapper named JSTONE uploaded a freestyle rap over it, which got recognized by Joel, but not much happened other than that.
* CowboyBebopAtHisComputer: [[https://twitter.com/deadmau5/status/280920822577782785 Right here, and lampshaded.]]
** Apparently, [[http://deadmau5.tumblr.com/post/61526512529/damn it gave him ideas.]]
* CreatorBacklash: Sometimes overlapping with OldShame.
** Joel has openly spoken out against his work with MELLEEFRESH between 2007 and 2008, as the songs produced from their collaboration routinely included vapid lyrics about being the biggest whore you possibly can, which have rendered them unlistenable to him. (Song names include "Sex Slave", "Attention Whore" and "Something Inside Me".)
** He has also disavowed the various ''At Play'' compilations from his former label Play Records for repackaging and remixing his Melleefresh songs, as well as other recordings from that era, without his involvement or permission as cheap cash grabs. [[https://www.hollywoodreporter.com/thr-esq/deadmau5-sues-remixes-mashups-834630 He would eventually sue Play Records in 2015]] for their unauthorized remixes.
** "Raise Your Weapon" is a minor one for him now, due to him basically admitting he made a dubstep song to sell out, and that he pretty much hates dubstep now.
** Slightly before ''W:/2016ALBUM/'' came out, Joel admitted that he didn't like the outcome of the album, stating that it was inconsistent, "slapped together", and that he only made it because he had "fuckin' mad bills" to pay off. He did, however, say that "Snowcone" and "Whelk Then" were two songs off the album that he genuinely liked.
** He said the following about "Hey Baby":
-->"[[https://twitter.com/#!/deadmau5/status/174345422071021570 its a fuckin stupid song. really it is... not sure what i was fucking thinking back then.]]"
* DevelopmentHell: ''United We Fail'', his upcoming graphic novel project, is currently in this, if not outright on hold at the moment. He cited ExecutiveMeddling "making it not fun" as why.
* ExecutiveMeddling:
** "Ghosts 'n' Stuff" was originally titled "Ghosts 'n' Shit", but his higher-ups wouldn't let him release the song with that title.
** In [[https://www.youtube.com/watch?v=auzdtl-aLQs a stream he did on January 11, 2012]], he called up his manager and asked to release "Maths", then stated that it would come out later that week. "Maths" wouldn't come out until a ''month'' later, and [[http://deadmau5.tumblr.com/post/17312022683/when-are-you-digitally-releasing-maths-i-only-ask he confirmed that it was because of this]].
** ''United We Fail'' was put on hold in part because of this, as he was sick of the suits and businesspeople getting involved in the project and making it "not fun".
* InMemoriam: On June 3, 2007, Spanish producer and music software creator Arguru (real name Juan Antonio Arguelles Rius) died in a car accident. Soon after, Joel and DJ Chris Lake produced [[https://www.youtube.com/watch?v=hLALcdmxbh4 this track]] christened with his nickname in his honor.
* KeepCirculatingTheTapes: There are numerous songs that are on his [[http://soundcloud.com/fuckmylife/ SoundCloud]] and Website/MySpace accounts that haven't been officially released or even made available for download. These not only include rather...''{{o|utOfGenreExperience}}dd'' songs, but earlier versions of existing songs (such as "Old Ghosts" - see WhatCouldHaveBeen below), remixes of existing songs, and live edits. Due to his [=SoundCloud=] account being wiped in 2014, his uploads on that account are even harder to find than they already were and only survive due to fans preserving and sharing them online.
** All of his early work fits under here, especially since Section Z, the music site that hosted it, is now gone. ''Project 56'', ''deadmau5 Circa 1998-2002'' and ''A Little Oblique'' are compilations featuring much of his early work. Many one-off tracks are circulating around the Internet as well, such as "asdfghjkl", "Limit Break" and "Brazil".
** "October" reached memetic status in this regard, originally appearing in a handful of live shows in 2008. It finally saw release on ''> album title goes here <'' in 2012.
** For unknown reasons, his debut album ''Get Scraped'' was removed from digital storefronts and streaming services in 2018. While some of the tracks were rereleased on the ''Stuff I Used To Do'' compilation, many of the tracks are still unaccounted for and can only be found through digital copies uploaded and shared through the Internet by fans.
** Even scarcer is ''Get Scraped''’s [=CD=] version, which had a different tracklist and two songs [[MissingEpisode omitted altogether]] from the more easily circulated digital version (though one of those tracks would be rescued on the aforementioned ''Stuff I Used To Do''). The [=CD=] was limited to 500 copies and is so rare that '''''no''''' copies have even surfaced on Discogs, with the only evidence of its existence being a handful of online store listings and the two missing tracks circulating on the Internet.
* NewbieBoom: After "Ghosts N Stuff".
* ReclusiveArtist: Starting in the late 2010s, Joel has become significantly less active on social media as a whole, with both his [=YouTube=] and Twitter accounts mostly being used for promotional purposes as opposed to his more silly and interactive persona seen in previous years. He does still stream on Twitch on occasion, however.
* ReferencedBy:
** ''VideoGame/DiabloIII'' contains the amulet "Halcyon's Ascent", which is visually reminiscent of a mau5head, is named after Joel's early "[= Halcyon441=]" handle, and has FlavorText that reads, [[WaxingLyrical "Raise your weapon, raise your weapon... and it's over."]]
** After Joel established himself to be a huge ''VideoGame/{{Minecraft}}'' fan in its early days, Mojang returned the favor by immortalizing him in one of the random splash texts on its title screen: "Joel is neat!"
** In ''VideoGame/{{Overwatch}}'', Lúcio is a Brazilian DJ with [[AnimalMotifs a tree frog motif]] that has a couple of alternate skins with helmets visually reminiscent of mau5heads, just made to look like a frog instead of a mouse.
** ''VideoGame/{{Paladins}}'' features the playable character Maeve and her ElectronicMusic-themed alternate skin, "Raeve Maeve". Her [[AnimalMotifs cat-themed helmet]] ''might'' be a direct reference to mau5heads (or just [=DJs=] with cool helmets in general), but there are also a few direct references in her dialogue: "So much for being a ''ghost and stuff...''", and "You're like a ''dead mouse!''"
** In ''VideoGame/Splatoon2'', the InUniverse composer for ''[[ExpansionPack Octo Expansion]]'' is a [[AndIMustScream sanitized]] Octoling named [=Dedf1sh=], whose name and the fact that most of the music in ''Octo Expansion'' is house techno are a combined reference to deadmau5.
* ScheduleSlip:
** His new studio and house renovation was originally supposed to be done in December 2011. The end-date for the studio was moved to February 2012, and then ''again'' to March 2012. Consequently, the official release of "Professional Griefers" and the album, ''> album title goes here <'', were also pushed back.
** As seen in ExecutiveMeddling above, "Maths" was originally supposed to be released in mid-January 2012 before coming out around a month later.
* WhatCouldHaveBeen:
** Feast your ears on an [[http://soundcloud.com/fuckmylife/old-ghosts old track]] from 2004 that later became "Ghosts 'n' Stuff" after ''at least 10'' revisions.
** "Brazil" was originally much more [[https://www.youtube.com/watch?v=R2jBI_eixvU chill and meditative]], and is completely unrecognizable from "Brazil (2nd Edit)."
** It was mentioned in a livestream that he had actually received several vocal submissions for "Maths", but decided to keep the song as an instrumental.
** He said on Creator/JoeRogan's podcast that he was one of the artists considered for doing the soundtrack to ''Film/TronLegacy'' before Music/DaftPunk was chosen, and added that had ''he'' been chosen and found out that Daft Punk was being considered, he would've handed it off to them anyway.
** He stated that he'd gladly remaster the tracks on ''Get Scraped'' in his new studio...but he can't, because [[NoPlansNoPrototypeNoBackup he doesn't have the source files for them anymore]].
** After the release of the ''7'' EP -- consisting of seven piano pieces based off the SevenDeadlySins -- Joel considered doing a sequel EP based off the SevenHeavenlyVirtues, reportedly featuring more analog synths. He ended up [[https://i.imgur.com/qmXIOjH.jpg teasing their existence as a work in process]], but after 2014, only "Castitas" was released as a demo on his website, with the rest of the EP falling (ironically) into DevelopmentHell.
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