Disagree. There's an abstract "information space" that the code is modeling, and you have to move around your mind's instruction pointer in that space. This can

Disagree. There's an abstract "information space" that the code is modeling, and you have to move around your mind's instruction pointer in that space. This can be helped or hindered by both mutable and immutable vars--it depends on how cleanly the code itself maps into that space. This can be a problem w/ both mutable and immutable vars. There's a slight tactical advantage to immutable vars b/c you don't have to worry about the value changing or it changing in a way that's misleading, but IME it's small and not worth adopting a "always use immutability" rule-of-thumb. Sometimes mutability makes it way easier to map into that "information space" cleanly.