I've never found a use for the key inventory - once you have a key, it just works when you need it so why do we actually have an inventory? Of course, it doesn't do any harm and the keys don't weigh anything but is there a point? This is one of those innocuous things that's easy to ignore but maybe there's a real purpose?

Thanks!

Why not have one? It lets you see what keys you have, and it lets you put down keys you don't want to carry with you. Useful when roleplaying. At least they've put it in a category of its own now. In Oblivion and Morrowind, they weren't and towards the end of a character, if you didn't regularly deposit keys in your house or something, you'd be faced with a huge blockade to traverse to get to the repair hammers, soulgems and other misc object

Not sure I understand.

To use a key, you must have it in your inventory. If it's not, you can't open the door.

What he means is the fact that you will never actually go into the inventory to use said keys. That combined with the zero weight makes it pretty much pointless to even look at them let alone have an entire section just for them. I do agree though it is nice to not have to wade through them in the misc section, so I guess that might be the reason.

Before, when we had Keys, they were just mixed up in our inventory with everything else. They implemented a "Key Ring" feature that hides the keys. I think the earliest versions of Oblivion had this issue, and too many keys would crash the game when you opened your inventory, hence the Key Ring. In Skyrim, they just give it a different category like the Potions and whatnot.

I could see a thief character seeing his key inventory as trophy.

I see, kind of a legacy thing and kind of a role-playing thing. Cool, thanks. I just wanted to be sure there wasn't some secret uber-key or loot that becomes visible once you have every key in the game. It suddenly occurred to me that maybe this is some sort of counter. Thanks.

Ah the key section in the inventory? I regularly take a look at it, especially when I don't remember who my character decided to follow at the beginning: Gerdur gives you a key, Alvor doesn't.

I had to regularly drop keys from my Inventory in Morrowind. I used to use one chest for this in my house mod and it was a way to keep track of where I have been.

Wouldn't it be cool if thieves could build some sort of Hearthfire key cabinet for exactly this reason - a trophy cabinet. That would be really neat.