As Advertised.
You look, but you don't see. He says "There is someone I have sworn to kill" and dismisses dreams as just a word. All you do in think to yourself, in one way or another, 'as expected' and carry on. You don't ask any other questions. You accept, and he accepts what is expected once again.
You don't ask what he will do once Itachi is dead. You don't ask how hard he's willing to train to reach that goal, his plans for reviving his clan, the jutsu he wants to create that will defeat his brother. You don't comment on his angsting or preening, the fixation on being the best, his need for praise and attention as glaring as Naruto's. You just accept that he is an genius avenger and leave it at that.
You don't see that he just wants you to say that he doesn't have to. More than anything, Sasuke wants the villagers to say "Enough death." He does not want to have to kill his only brother. He is afraid of his brother, afraid that he won't be strong enough to face him alone. And alone he will be when he faces Itachi, because we will step back and allow him the 'honor' of vengeance. We are too chicken-s--t to go after the kin-slayer ourselves, so we wait for a little boy to grow up and do it for us. We are such a strong family in Konoha that we make our children into the agents of our vengeance. Such hypocrisy.
We tell him that he will be that strong, heaping admiration and praise upon him, wondering at his talent while secretly hoping that his talent won't lead him down his brother's path. We praise the talent and disregard the training. The unending training early in the morning and long into the night, collapsing into a dreamless sleep to avoid the nightmares. Games that must be disguised as training, moments of peace forced down his throat or carefully hidden from villagers who disapprove. After all, the last Uchiha should not be seen to be too happy. That would be disrespectful towards the dead. Sweet rare smiles shine like candles in a long darkness.
What will be after the vengeance? And in the middle times? Will the shadow of that day stretch forever into a future made bleak and lifeless by expectation. Those are the questions we didn't ask. Now we can't. You were all shocked when he left. After all, you'd given him access to high level Jutsu, isn't that affection? You declared your undying love for his super-cool brooding persona while using him as a pawn in a contest with your best friend, which everyone knows is a great way to make a person feel special. And his rival/best friend incidentally made the object of his vengeance ignore him as unimportant and weak. Being stuck in a coma for weeks while said rival travels, meets several important people, and learns a very powerful and exclusive Jutsu was just icing on the cake of love and happiness.
He pursued the vengeance expected of him. He sacrificed the present for the future. We said "You must be the avenger of your clan." until that became inconvenient, then said "Leave off this vengeance until your older." But until Itachi is dead, Sasuke will never be able to grow up to be who he wants to be. He will live forever in that shadow until he removes the one blocking his light. Even if he must die to do it, some part of him will die free, knowing that the ghosts of his family and the village's expectations will not haunt his next life.
So he seeks the power to do what is expected of him. Because that is all he has left to dream of. He is an ungrateful little punk with no sense of team-work or humility. He is an angsty goth with a lifetime of complexes and the mind of a papranoid genius trapped in a 12 year olds body. He is the cold-blooded Avenger with no time for human considerations. Exactly as Advertised.