Literally everything Sasuke ever done and chose to do went to extremeties that made little to no sense. I do understand him isolating himself as a child because of what happened to him, but as he grew up his ability to make decisions in a reasonable way went down the drain
Sasuke was almost there till the end of Part 1 when he decided to go crazy hungry for power, and thought killing his friend was right because his brother told him it was (at least he changed his mind but still). Then in Part 2 when it started the fact that he tried killing Naruto AND Sakura when they finally meet again was beyond ridiculous to me, although it was funny watching him neg them.
Then after he learns the truth baffles me to this day. Seriously, after learning that Itachi CHOSE to protect the village and was not FORCED to do his mission, you think its the Hidden Leaf's fault? That can't even be pinned on the Uchiha's curse of hatred thats just Sasuke being mentally weak to make decisions reasonably. Kishi could have wrote Sasuke better in terms of personality but nah he only decided to give him great abilities
Let me explain.
Assume that up until the Massacre, Sasuke has normal memories and dreams, akin to you or I. Then take into account that the Sharingan creates photographic memory when it is active.
The first clear, permanent memory he ever developed is of his family's massacre. So as the visions of his family obscure, one thing, no matter what he learns, stays there. The image of his family's murder replaying over and over, his only real memory of them. Keep in mind, he didn't reawaken his Sharingan until Zabuza's fight, so for years, that is literally the only thing he can recall with 100% clarity.
It's not something he can put behind him, because, if he can still remember the number of leaves on the floor that night, but can't remember whether or not his mom has a mole on her shoulder, how is he going to end the grieving process?