But then how do we determine who has priority for the couch? The singleton nature of the couch requires some form of access control to prevent disputes. No such restriction exists for a memory of the couch, once we have each been exposed to it we can enjoy the memory perpetually and simultaneously with no conflicts.

Artificially restricting what can be remembered and by whom solely on the basis that some forms of memory produce new physical artifacts ("copies") is absurd on its face.

That said, the ability to monetize a memory is much more like the couch. In theory this is the resource copyright aims to protect. In practice, experts disagree to what extent piracy impacts potential monetization leaving us with two sides of the debate tending to talk past eachother.