He would've know about the advantages of shadow clones. I remember earlie in part two he used to speak to naruto and all of a sudden puffed to smoke making everyone realize he was a shadow clone and annoying naruto... But more to the point, in those conversations he would've been informed of...
1.lee and naruto because of their attitudes
2.hinata
3.haku
4.haku
Lol jokes
But for 3 and 4 I don't know because any character that would have a deep enough personality to hate actually fits well with the story... Like how people claim sasuke is selfish. Even if he is or is not suppose to be...
O____O
I.... I never realized... It's like nothings real anymore?!... WHO AM I?!?!
I always thought there was something wrong with his face. And here I thought it was his sinister look :)