And the game won't ever acknowledge that or reflect your character. You're just playing pretend like the people on the Oblivion wiki who write about how to "roleplay" a guard. It doesn't matter how hard you try to dress up and act like a guard: You still aren't a guard. People won't ever acknowledge you as a guard. The fact that you are a "guard" won't ever have an impact on the game.
Anyone playing any roleplaying game, whether pen-and-paper, live-action or computer, is playing pretend.
That is not a hallmark of a good role playing game. RPGs should reflect the character's abilities and the choices the character makes or there's no point in having characters, which last I checked, are indisputably integral to the concept of an RPG.
But my abilities and choices are "reflected": my kleptomaniac xenophobe has a shack so full of shiny things that the floor's no longer visible, and a mace arm steeled on the skulls of Cyrodil's beastfolk. My good-hearted little idealist has emptied the wine cellars of the province's mansions and distributed the contents to beggars' food baskets and the larders of the poor, learning in the process the art of moving unseen and unheard. Sure, being a C-RPG means there's limits to how much of this is recognised, but this will always be the case without the luxury of a flesh-and-blood DM.
Anyway: if Oblivion isn't an RPG then I no longer know what that word even means anymore, its descriptive value has been reduced to naught.
(RPG, sandbox game, first-person adventure, whatever, it's just semantics, and has absoloutely no bearing on the quality of the game in question, which is, as with all Beth's stuff, utterly consistent with their straightforward design goal "live another life in another world".)