As a Skyrim fan, what am I missing about Oblivion?

I love, love, love Skyrim - played it until my eyes went square. I've bought Oblivion, and I've tried to get into it a few times, but I just hit a wall with the mechanics and the gameplay. It might be the weapon degradation (never my favourite part of game design), but the conversation minigame doesn't make any sense to me, and neither does the levelling system.

I admit I'm not a big RPG aficionado, but one of the things I like about Skyrim is that it's accessible with a straightforward interface.

So: could someone tell me what I'm missing? What do I, as a Skyrim fan, need to change about my mindset to enjoy Oblivion?