Just seeing this for the first time after playing and finishing MOTHER for myself, it's so good.
The thing that's so intriguing about MOTHER 1 is that it's story is just as in-depth as 2 and 3, but we hardly see any of that story in the actual game. As far as I know, other than maybe the novel I haven't read, there's no official reason for why Maria and Giegue split up, why the Caves of the Tail and their pink shells that warp to Magicant are hidden around the US, why George's grave is atop Mt Holy Loly, or why Maria's memories are gone.
And while Kenisu3000's webcomic puts out interesting ideas and the pink shells were visually called back to with the Magypsies in MOTHER 3, who may be connected to Magicant in other ways, all this mystery just makes the already amazing game even more addicting to think about.