Glad they finally explained who "Natalie" is. It was a bit of a stretch for the viewer to believe that Daniel just happened to meet up with this same woman he saw so many years ago, but I know the writers had to make her a real person. If he's on his meds, he can't see her as a hallucination, so they had to bring her to life. I always look forward to the final moments when he's lecturing his class and the theme music builds under his words - love it! This episode was especially good at the end, because there was nice closure from the very first episode of the series - with Lewicki observing Daniel on the bench with Natalie.