The original title is "Python's Memory Model Is Not What You Think It Is"

Short summary

Python binds names to objects rather than storing values in variables—a subtle distinction that fundamentally changes how you debug mutation, function arguments, and aliasing. The same syntax (`+=`) behaves differently for mutable types (lists mutate in-place) and immutable types (integers create new objects), breaking the "variables are boxes" metaphor. Interview traps like persistent default mutable arguments become solvable once you trace code through this accurate mental model.

• •Python uses name-to-object binding, not value storage
• •Mutables mutate in-place; immutables create new objects (same `+=` operator, different behavior)
• •Default mutable arguments persist across function calls (classic interview trap)

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