Being optimistic isn't weird, it's simply hoping for the best while still thinking about the worst.

[And she's dealt with the worst for so long. Thinking that maybe things will get better is a reasonable response... right?]

...I'm not foolish, Byakuya. I know how tense the situation is, and just how easy it might be for someone to slip up and then... something happens that everyone will regret. I just want to believe that it wont.