Hi N80 and welcome to the crazy world of audiophilia.
My all-time favorite post here was the very first one from Nonoise. Yes, you've (re)opened a very familiar can of worms. And one you get guys like Prof & Clearthink going, forget a logical straightforward conversation.
I was wondering when somebody would mention a cable-cooker, and Geoff (and others) finally did. Someone advised buying 2 pair of the same cable, breaking one in and then comparing it to the new unused set. That'll work, but...
If you have access to a cable-cooker, you won't have to wait so long. Put one set on the cooker for 48 hrs. and THEN compare them. Have a friend swap the cables out so that you, the subject, has no idea which is which. Go back-and-forth several times.
If you hear no difference, perhaps you're right that this is all negligible to you.
One last point; the notion of burn-in as a marketing ploy is nonsense. In 40+ years of this hobby (obsession?), I've never heard a dealer or mfgr. tell any dissatisfied customer to "wait for burn-in".
Now OTOH, I know of a few cable mfgrs. who burn their cables in before selling them and do not advertise that fact. That IS a marketing ploy, in that they know their cables will sound better than many 'right out of the box'. (It's also a nice convenience for their customers who do not ave access to a cable-cooker.)
You can tell that I'm not a skeptic on burn-in. Why? Because I've done what I described above many times with different cables and other 'subjects' listening as well. But each to his own; The only things that counts are what you hear and whether it brings you some joy.
Happy listening!