Dumb question #643: should speaker cables last a lifetime?

Let's look from technical viewpoint.  Small amount of DC voltage on the amp's output, always present, causes drift of electrons called "drift velocity".  After a while all high quality electrons, that you paid for,  will be replaced by plain ordinary electrons.  

Nice K!   (Pssst ... Stereo5: he's kidding ; )

Thanks for all the info. I'm almost 50, so I'm probably good on the lifetime part. 

Jafant, what you say makes a lot of sense. I guess with anything, stereo, cars,etc, no matter how high of quality, it will eventually be imporoved with something better. 

if you feel a need to replace be SURE you can return the new ones if they don't sound better to you

Beware placebo effect and use blind testing

Distinguish new cables from just making a new connection (see corrosion comments above)

Speakers are most important, followed by room treatments - upgrade those things first.

I had a set of cables with a clear covering and over 15 years all the copper inside the cable also oxidized, turning green, not just the ends. So I assume that even good quality cable might slowly deteriorate over that period of time