So the recently released video âWhat did Zoey Say?â got me thinking about the shows I grew up watching on Nickelodeon.  And then I started thinking about how all the universes meshed together, and I hit a roadblock.
So, iCarly and Victorious canonically take place in the same universe, as they were able to go to that party together at Kenan Thompson's house, in "iParty with Victorious" and have Sam and Cat create their own babysitting business, in the show Sam and Cat.  iCarly and Victorious do not, however, exist in the same universe as Drake and Josh, as both iCarly and Victorious have cited Drake and Josh to be a TV show.
But here's the thing: in one of the episodes of Victorious, "Helen Back Again," Hollywood Arts gets a new principal.  Who's the principal?  Helen, the zany boss of Josh and Crazy Steve who was fond of Drake. The Helen in Victorious shares the same canonical background as the Helen in Drake and Josh, having been the owner of the Premier and the former child-star in whose famous line was "that is not my job."
Two other characters from Drake and Josh, Craig and Eric, also make canonical appearances in iCarly, when the web-show crew heads to Webicon for the first time in "iStart a Fan War."
Also, many of the companies and attractions shown to exist in Drake and Josh, often parodies of famous ones like "Mountain Fizz," "Galaxy Wars," and "Pear Company," have made appearances in the shows iCarly and Victorious.Â
 Additionally, in Zoey 101, iCarly.com is shown to have existed, so iCarly and Zoey 101 must be in the same universe.  This fits in with the fact that in one of the episodes of Zoey 101, Drake Bell, not Drake Parker, plays at a school event, the Spring Fling that Zoey and company had organized, in the episode "Spring Fling."  Later, however, in an episode of Drake and Josh, Josh pulls up footage of Drake playing an event as Drake Parker.  This footage is the same as that from the episode of Zoey 101.
tldr: I am an obsessive wierdo who hates continuity gaps, especially those in the Danwarp circle of shows.
EDIT: It has been brought to my attention by tumblr user animefan101 that in the show Sam and Cat, neither knew the other despite being introduced during the party in iParty with Victorious, Â This only deepens the mystery - did both girls, who are canonically the same people as in their source shows, suddenly get amnesia or what? Â
