There are indeed some nuances you are missing as well as at least one misconception you are holding: > The idea that I can touch variables that have gone out o

There are indeed some nuances you are missing as well as at least one misconception you are holding: > The idea that I can touch variables that have gone out of scope (and that have ostensibly been GC'd) You can't touch variables that have been garbage collected, indeed. A variable captured in a closure will have a reference to it and therefore not be garbage collected until the closure itself goes out of scope and is garbage collected. Closures allow encoding some state into a function, which is especially useful for higher order functions that return specialized functions, for example. This is, for example, how decorators in Python work - a function is captured in a closure, which is then referenced and called by a new function wrapping the original function.