Lirael is the equivalent of being blind, deaf, mute or lame, or even severely dyslexic, in our culture. Everyone will be kind and understanding, but always treat you as being "different," when really, you just want them to stop being nice and treat you like they do everyone else. (Comparatively, Sabriel is the valedictorian, and Sameth is whining about being quarterback, or something along those lines.)

But yeah, I really liked the trope bending there. And really, I liked the trope bending with sameth, too (the "chosen one" who doesn't want to be chosen, and always knows about it instead of having it sprung on him, only to learn that nope, he's actually a little closer to normal) I just couldn't sympathize with him.