I was thinking a little bit about the two debates that are pretty emotionally charged. One of them is with regards to whether or not time travellers gain new memories of the new timeline(s). The other one is with regards to whether or not Doc would stay in the past with his his family, or if they would eventually move back to the future.

With regards to the memory thing, well, you actually have see the bigger picture. Like what exactly happened to the Marty of the new timeline? Did he basically "die", by disappearing entirely out of existence? Or did he simply merge with the Marty of the old timeline? To me, the latter seems to be the most feasible. It's understandable that Marty may feel as his past from the original timeline is the most real to him - but, in fact, the past(s) from the new timeline(s) would be just as real.

So what about the scars issue? Well, if the Marty of the new timeline had different scars from the Marty of the old timeline - well, the new timeline would automatically override the old timeline. It would be like if Marty went back to the past and caused his younger self to accidentally break his leg. I think you get the idea.

So what happens after the Marty of the new timeline goes back to 1955? Simple! He just has memories from the old timeline. That way, he would do everything as it happened the first time around. However, after going back to 1985, he would soon remember both timelines.

With regards to the era in which Doc would live out the rest of his life, I'd have to say he's eventually go back to 1985, or some time thereafter. In addition to not liking the idea of Marty and Doc being split up forever, Doc staying in the past with his family would be too risky on the space-time continuum. I also admit I'm partial to the idea of the kids spending some time in the 1980s.

It does seem like, at the end of the trilogy, Doc was planning on staying in the past with his family. However, why would he go through all that trouble of creating a time machine just to pick up Einstein and give Marty a souvenir? When he planned to stay in the past, he already told Marty how to take care of Einstein. Then there's also the fact that he hover-converted the train. So I'm of the school that he already had plans to move back to the future, but he just wasn't sure when. So he temporaily decided to relieve Marty the responsibity of taking care of Einstein.

In a side note, I really don't understand who some people strongly hate Clara. I can understand not liking how Clara messed up the Doc/Marty dynamic - but it's usually Doc fans who have a strong dislike for Clara. If it's simply because they're jealous of her - I think that's silly, as Doc is a fictional character. Maybe they don't like the way she's tamed Doc, but was already tamed by the eight months he stayed in the Old West. I'm not especially fond of her (simply because I've never really connected to her), but it's nice for Doc for find true love.

I agree with everything you said. For instance, Marty's personality did seem to change once he went back to 1985. He became a more experienced time-traveler. And he has a newfound hatred for being called names.

Yeah, he didn't seem to have the chicken problem in the first movie. Of course, we never hear anybody calling him a "chicken" in the first movie - but I figured that something about Marty's personality would probably be different, so I just went with that one. He seemed to have a lot of confidence in both timelines - even though he starts to question how good he really is after audition, but it's just because he's having a low moment. Other than that, I'd probably say both Martys are pretty much the same. Everyone else in his family seems to have changed drastically, though.

I think George, Lorraine, and Linda have definitely changed for the better. I am questioning Dave's change, though. Sure, he becomes more successful, but he seemed so much grumpier. In the Twin Pines Universe, he was happy and fun-loving, despite working at Burger King and having to take the bus to work.

Yeah, he did seem pretty grumpy, didn't he? I guess he became a "suit". I wonder how Dave would get along with Brantley Foster or Alex P Keaton. He was pretty goofy in the old timeline, but he seemed like a more pleasant person to be around. He was probably one of the very few close buddies George had. His wife basically ignored him, while Marty and Linda had expressed some disgust in him.

A fanfic written by Blind Spot suggested that Lester the Wallet Guy works at the same office as George and Biff.

In your stories, George is still good friends with Billy Stockhausen in 1955. What happened to him by 1985? Did George and Lester lost touch with him after high school?

Hm, that's a good question. I guess it depends on which timeline you're talking about. They very well could have lost touch, but they maybe could've stayed friends. I haven't really established that part so much.

I really like Blind Spot's story, I'm In 1985 Butthead (something like that, anyway), where Biff stows away in Marty's DeLorean to 1985. Then there's also a story by Nightspore called But At My Back I Always Hear with a similar plot - only it's George who stows away in the DeLorean. He usually writes George/Marty slash, but there's really no slash in that story. That's the nice thing about the time travel nature of BTTF. People can write AU stories without being criticized for it. You can think of the AUs as simply being parallel universes.

Here are some of my major thoughts on the whole memory issue:

Q. What does LP Marty remember, after returning to 1955?

A. It is my theory that, in with preserving the timeline, LP Marty basically turns in TP Marty after returning to 1955. If he retained his LP memories, he would be likely to do things differently, drastically messing up the timeline. Also, it would nullify much of the events we see in Part One - and hat just wouldn't be right.

Q. So that that mean LP Marty disappeared forever?

A. Nope. While Marty will initially remember only the TP timeline after returning to 1985, the ripple effect would soon cause of to remember two timelines. Within time, his memories of the LP timeline will be clearer - while his memories of the TP timeline will be more fussy. However, his memories of the TP timeline will never fade away completely.

Q. So does this mean LP Marty and TP Marty basically merge together?

A. Yeah, merged - or, if you prefer, fused together. Neither past is more "real" than the other. Any subtle changes in personality may cause some inner conflict, but that's only temporary. Within a matter of one week, Marty should be used to the changes.

Q. When does 1985 Doc in 1885 start to remember the second appearance of Marty in 1955?

A. This is probably the hardest question of all, because of the whole "gravestone idea". I don't think it is necessary for Doc to fabricate his own death and build a new gravestone. After some heavy pondering, I've decided that the Doc of the final timeline doesn't remember seeing his gravestone in 1955. He would only remember the events that would occur in the final timeline..

Q. Okay, but when does 1985 Doc in 1885 start to remember the final timeline?

A. My original belief was that Doc wouldn't remember until after moving his family back to 1985. However, I think I would remember shortly after Marty was sent back to 1985.

Q. So what if Marty was stuck in 1955? When would he start to remember the new timeline?

A. Probably not until after his younger self is sent back to 1955.