I know of that which you speak.

My interpretation of events (with interest in neuroscience) is that your brain adapts to having constant stimulation from smoking and so the effects linger because your brain has slightly altered itself to compensate for the change in neurochemistry, insofar that your thoughts are physically laid down within your brain, so enough of a certain kind of pattern (if you will) starts to cement that pattern. This is the same variability that allows for brainwashing, etc, and even more basically for personalities to take shape.

Flip the world upside down with goggles and you'll be riding a bike and catching balls within a week or two (although at first it is completely disorienting and you become instantly deficient at most any physical task).

Our brains are wonderfully adaptive organs.