So here is a long theory on Rick's actual origin and his relationship with Morty.
In the case of TL/DR. Below is the short hand version.
Ricks from a different reality C137 is his origin reality and he ruined that one and morty died. So he came to a new reality and set up shop.
Long Version
In R&M, Rick shows up and has been part of the Family for the last year. After being absent for the previous 20. That we learn in episode one. As the season progresses we continue to learn about Rick. He is a genius that is broken, hurt, and cares solely about his own needs. At least that is what we believe through most of the season.
In Ep. 10 Close Rick-counters of the Rick-kind, he is called Rick from dimension C137. When Rick is captured by the Scar Rick and his mind is being scanned. His memory's are being shown on the screen. The memory's show alot of Rickish stuff, then it focuses on Morty. Here is where it gets interesting. In his memory, Rick is picking up Morty as a young child. It then shows a sequence of shots of Morty from Ricks eyes on some of the adventures from season 1.
Thing is that Rick has only been in Mortys life for the last year. Before that he was gone for 20 years as stated by Beth. That along with the Wubba Lubba Dub Dub and his heavy drinking lead to the fact that this Rick is from another reality. This worlds Rick is dead and he took his spot same as R&M did in Rick Potion #9. Assuming that, then one can hypothesis that this Rick's Morty died in his reality or on some adventure. He came here after he ruined his reality or could not bear to go on without Morty.
