Sasuke isn't anything like how most people see him. People know that he's quiet, talented, and trains all the time, leading them to thing he's obsessed with revenge against Itachi. In actuality, he's quiet, a bit of a coward, has very little ambition, and trains like he does so that he doesn't end up dead during a mission. It's not his fault he's as naturally talented as he is. Nevertheless, people draw their own conclusions, and according to Sasuke, they're usually way off the mark. Initially, the story appears to be canonical Naruto told from Sasuke's point of view, although it eventually becomes clear that it's an AU.
Over time, due to luck, ninja training, and the terror of being interrogated if he breaks character, Sasuke gains a reputation as a hero. And he hates it. And it is hilarious. As Sasuke himself puts it, "Looking back, I can see how much I should have been able to predict about the rest of my life by this first encounter. It had all the elements. Confrontation with stupidly overpowered ninja. Naruto being a suicidal idiot. People somehow managing to mistake my self-preservation for bravery. And “rescues” or “help”. Let me be perfectly clear, were to be strapped to operating table, and I had a choice between Orochimaru himself to try to cut out my eyes, and my teammates coming in to “rescue” me, I would pick the snake. Every, single, time."