Sasuke told him last chapter, your forgot the whole conversation with Kakashi about a new Uchiha being unlikely therefore he set off to tag along with Sasuke and meet Orochimaru.
Welcome to the bandwagon the existing members and newcomers, currently we are being kinda stupid and reiterating the same thing that first two posts already said in hope of some points and to suck on someones witty response like a leech.