We didn't forget. Mostly because that didn't happen.
Originally posted by: XanBcoo
Yet after he learned the Chidori, dramatically increased his speed, and unlocked his Sharingan further, he would have been strong enough to go head to head with Neji without resorting to the curse seal. Maybe he wouldn't have won, but I think he'd be able to hold his own. He's a genious ninja, strongest of his class, and has the Sharingan. Don't take him lightly. The curse seal just guarntees his win [img]i/expressions/face-icon-small-tongue.gif[/img].
Oh don't misunderstand, I'm not saying that Sasuke as he is now, or even after Kakashi's training couldn't defeat Neji. I'm just saying that at one point in time, he wouldn't have stood a chance.

Afterall, there was once a time when Itachi would be killed by kakashi without any significant effort, but that time is long gone.