Rick and Morty finally explained Rick Sanchez's full, and tragic back story at last with the final episode of Season 5! As promised by the executive producer and showrunner for the series, Scott Marder, the final episodes of the fifth season had finally delivered on the major canonical and character shifts that fans had been hoping to see throughout the rest of the season. This was especially true for the final episode of the season that came with some major status quo shifts as the titular duo learned more about one another.
With the return of Evil Morty to the series, fans finally got some explanations as to many of the lingering mysteries about the Citadel and Rick himself. Throughout all of this, it's revealed that Rick's mind was indeed successfully scanned in a previous season and with it came Rick's full and true back story. With Morty diving into this flashback, we learned how much Rick had lied about and what parts of his past he was telling the truth about.
The final episode of the fifth season, "Rickmurai Jack," saw Morty plug himself with the brain scan of Rick's past and through a flashback we learned that the previous version of Rick's past was actually true. While he tried to say he made up watching his original Diane and Beth die right in front of him at the beginning of the third season, the flashback reveals that this actually came to pass and sent him down a dark and lonely path.
Picking up from their deaths, Rick then starts to experiment with his portal gun and begins exploring the multiverse. He starts to make the connections we see in the series, meets Birdperson and joins the resistance, and after he's rejected by Birdperson, Rick then goes on a mission to hunt down all sorts of variant Ricks in search of the one that killed his family. When he fails to find the exact one, he then goes on a drunken bender where he kills a bunch of other Rick variants.
The Ricks then decide to worship him and with his supervision, Rick forms the Citadel of Ricks and leaves it behind. From here he crashes into a different dimension's version of Beth's house (one of the "abandoned Adult Beths" alluded to in the eighth episode), and hangs out with her son Morty, and this turns out to be the ones we know.
But what do you think of Rick's true and full backstory? Let us know all of your thoughts about it in the comments! You can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!