Cable auditions - Hard Work?

Does anyone find it to be "hard work" to audition cables? I find that I have to be 'fresh' before I can begin to listen to cables. After I begin, I can only listen, with the intensity needed, for a period of about an hour.

As I do A/B comparisons, it sometimes seems, my impressions change as I listen. Sometimes the differences are so small or subtle, that I question if I'm hearing a difference at all. Have I lost it?

How do you folks do your cable auditions? I'd really like to know.

Thanks
paul