It's the smell, dammit.
Sight's and sounds can evoke memories of events. Only smells can evoke memories of feelings. Not real feelings, but memories vivid enough that they feel real. Ashley's house has a very distinctive smell. It's probably the smell of all the animals carrying out their lives, but to me, it's the smell of everything I've had with her. It's the smell I can't stand. If it weren't for that smell, there wouldn't be a problem. As it is, it was like, the most akward party ever. All because of the smell of a relationship. It's interesting, really. You don't think of smells like that normally.