@Luya I've been having the same thought regarding his sharpened senses, but it has been 5 years after all, and she probably served him a few months at most, so it makes sense his memories are a little washed. I think he does "recognize" her voice, that's why he says things like "you're so much like her", but he must have convinced himself that she is dead or something so he just won't believe it is actually her. I am so looking forward to the moment he finally acknowledges it is her.