Hey folks, newbie here.

Got a thought on the scene with Cooper and Diane outside the motel. I don't know how seriously I can take my idea, but it was fun so I'm open to critique.

Here goes:

When Diane sees herself outside of the hotel, she is really seeing Linda. Lynch shows us this to inform us that both Cooper and Diane have doubles in this new world they've crossed into. When the Cooper lookalike exits the motel that really isn't Cooper, it's Richard.

We "know" this because we've been prompted that they both have doubles, also when Richard walks to the motel door he stands waiting for Diane to join him (Cooper wouldn't behave this way -- he would have opened the door for Diane, reference later when he opens the car door for Laura at the gas station).

So Diane ends up with Richard in bed. This is why she reacts the way she does. She realizes it's not Cooper and knows that it's Richard she is with. She realizes that she and Cooper have been separated between two worlds.

Cooper on the other hand meets and goes to bed with Linda. Probably without realizing it. But Linda realizes that it's not Richard (or really, that something is wrong between them) and probably has the same reaction as Diane did. So she leaves Cooper a letter calling him "Richard."

One may ask, why did Linda disappear when Richard walked out of the motel? Let's just say that both copies cannot exist in the same world. Think Quantum Physics and how the act of observation coupled with a decision creates a split were both realities occur (alternate universe).

So the moment Diane made her observation, Linda and Cooper were split into an alternate universe. That's why Cooper was in a different hotel and had a different car, etc.

Well, I had fun coming up with that. Now shoot it down. I don't even know if I believe it.

Thanks for reading!