I'm just wondering, what exactly did you think would happen when surpassing 999 save files? Y2K? Detonation of nuclear warheads? Your cat begins to implode?

^^^I thought the same

I haven't had the game as long as most, so my number is at 2157. Though it was only yesterday it was at 2013 I accidentally jumped pretty high in Oblivion (from 4000-odd to 9000 or so) because I downloaded a savegame and their number was way higher than what I was up to. I always save in a new slot. I can reset the savefile number but don't want to. I like to see how far I can get.

So what you're saying is that whenever you restart an old character, or start a new character, you make a bunch of new saves for that character so his/her save file covers the shown save list to limit the risk of saving over another character? And you do this for every one of them? I should try that!