(Ahh...sorry if this isn't allowed. I just currently joined.)
After seeing that depressing, yet amazing new episode, I Remember You, I've tried connecting a few things I noticed in the episode that could have also played some parts in old episodes.
None of these are actual facts; they're really just guesses, assumptions, or somethings I tried seeing that could be possible.
One thing I thought about was the list of things Ice King listed when he was flipping through his papers. "On this receipt, on this take-out menu, on these newspapers!"
I thought about it, and kinda guessed what some of those things may have been towards... the receipt could have probably been the one he was given after buying the crown. The take-out menu could have been from a seafood resturant or maybe an aquarium (because it had a fish on it) Betty and him went to. The newspaper articles... well..that part is obvious, they showed us one of them.
Another thing, after seeing Simon give her that doll, it made me think. What if Ash sold her doll to the same witch Simon bought his crown from? It'd be quite the coincidence but that would definitely be interesting...
Also, in one of the verses of the song/lines of the notes, Simon stated he remembers making Marceline frown. There was also a verse of him saying he needed to save her... so what if she maybe got into a bad state of sickness at one point back then? I remember back in the Memory of a Memory episode, Marceline stated something pretty creepy. "I'm hurting you because I love you." What if this was something Simon stated to her to save her life ... maybe even getting someone to turn her into a vampire so she wouldn't die of whatever was endangering her?
If all of that is thinking too far pass the limit, maybe in his random crazy states, he said that to her, which made her frown and caused him to blame the crown.
The last, but probably something everyone thinks of, is the wording of his writings. I think him and Marceline might have been close friends even before that moment. The way they presented it in the memory, he randomly found her crying and cheered her up with a doll. However, I don't think someone would remember and find someone super special for just giving them a doll and then leaving. I think they might have known each other maybe a bit before the disaster. Thouughh... I know most fans are smart enough to think of it that way ^_^; sorry if that was extremely stating the obvious.
Again, these are just assumptions people! They may not be close to the truth at all... I know everyone have their own view on what may really be going on and that's why I'd like to hear what you guys also think about your own connections you've noticed, or maybe comments on some I made or add ons to it!
edit: I'd like to add...have anyone else noticed the weird, small pink creature in Simon's jacket pocket in the last scene of the new episode, and the 2nd and 3rd stage he went through in Holly Jolly Secrets? Slightly weird... my guess is that...it either connects to those weird dancing things Marceline showed Finn and Jake in her first episode, Evicted. Or that it may connect to the pink kitty baby of Gunther...