I don't know what it is, but I'm just a "bear for (Catholic) detail" lately. (Apologies to Irwin Fletcher)
One of the first portable practices I learned as a Catholic was how to pray the Rosary. From somewhere or other I knew that you were supposed to pray the Joyful Mysteries on Mondays and Thursdays, the Sorrowful Mysteries on Tuesdays and Fridays, and the Glorious Mysteries on Wednesdays, Saturdays, and Sundays.
When John Paul II suggested the Luminous Mysteries back in 2002, I liked them a lot, and somewhere along the way I learned that you were supposed to pray them on Thursdays. But it wasn't until this morning, sitting in church, that I noticed how this knocks down the Joyful Mysteries to one day a week, while the Glorious Mysteries still had three days. No fair! It's especially too bad, I thought, because the Joyful Mysteries day is a perfect time to substitute the Franciscan Crown for the standard Dominican Rosary.
This has to be evened out, I thought. So, Fridays and Sundays have to be the Sorrowful and Glorious Mysteries, respectively, for obvious reasons. Given those necessities, I decided that the Glorious Mysteries should cede Saturday to the Joyful.
When I got back to my room, I looked in a Rosary pamphlet that I had picked up for the kids RCIA, and there it was, arranged anew just as I had decided. So much for paying attention to what I was doing all this time! Age quod agis, frater.
P.s. My hometown church is staffed by the Dominican friars. One time, after the Luminous Mysteries had appeared, I asked one of the friars what they were going to do about it, seeing as their traditional, fifteen decade habit rosary was now sort of obsolete. Would they upgrade to one with twenty decades? To my surprise, the brother seemed genuinely annoyed by the whole business, and by the failure of John Paul II to consult the Dominicans before "changing" their Rosary.