So it seems to be my turn now.
So I thought "Yeah, I'm missing a great deal if I don't put mods in Oblivion". So I just got a few hundred megabytes of mods, including and actually just limited to (without mentioning required tools, script extenders and etcetera), Oscuro's Oblivion Overhaul, Unofficial Oblivion Patch, not Galsiah's Character Development and DarNified UI.
After spending a while stuffing them in using the Oblivion Mod Manager, I happen to be unable to go beyond the main menu. I uninstalled and reinstalled the whole game, then the mods, only to see the same effect. I performed some retries with a different set of mods, and they were preventing me from having OOO. This, until I decide to install OOO before anything else. That worked. But then, some time after I started a new game,... it just stopped feeling fun, and I lost the mood for it. Whether it was the fact that everything turned, as expected, harder, or that I just don't quite enjoy heavy and strong characters, I do not know. If only the next few hours after that had been productive...