I clearly hear the difference in cables sound after they have been in my system for what we refer to as the "break in or burn in period".
Like others, I cannot explain it. But I still believe that it is our ears/minds that are breaking in and becoming familiarized with the sound, and it has nothing to do with the wire itself.
I wonder if persons who have cable cookers hear any change in sound at all after they put a fully cooked set of wires into their systems?