"Hi..." The look on his face is enough to tell her what she dreaded to know. That she was just another girl. He had no idea who she was. No memories of how she had defended him, followed him around, treating him with the respect that no one else had shown. Tears began to form, but she quelled them. They wouldn't help. Because he hadn't actually ever consoled her after a fight with Buffy, or secretly let her read about the demons in Giles's books. He'd never said he wished Buffy'd been more like her, willing to learn from him rather then ignoring the council at every turn. He didn't have the memories that she did, because the monks hadn't bothered with the LA gang. Just as Angel wouldn't have remembered saving her from a group of vampires that were holding her hostage because she was the Slayer's sister and Cordelia wouldn't remember babysitting her when the other's went on patrol, he didn't remember the time she had 'accidentally' left her diary open when they were the only ones in the library, and hadn't been able to look her in the eyes when he told him about he and Cordelia.
He just didn't remember because it hadn't ever happened.
"Do I know you?" She bites her lip, and looks away.
"No. Sorry. Never mind." And she walks away, without looking back. Without telling him who she is. Because what good would it do?
Note: Yes it sucked. But I had to give Dawn/Wes a shot to see why I hated it. Now I know.