Swampman
Would a perfect duplicate have your meaning and memories?
The setup
Swampman compresses a large philosophical issue into a small imaginative case so the hidden assumptions become visible.
Why it matters
The case remains useful because it separates quick intuition from the principles people use to defend that intuition.
How to discuss it
Start with the simplest version, name the rule you are using, then test whether that rule survives a nearby variation.
Discussion questions
What intuition does this experiment test?
Which assumption makes the case feel difficult?
How would your answer change if the stakes were personal?