How we cite our quotes: (Chapter.Paragraph)
Quote #7
"How are you feeling, Nick?" Jamie inquired, shifting uneasily on his seat. He and Mae looked rather alike just now, both staring at him with wide, frightened eyes. He recognized with a shock the fact that they both looked worried. (10.39)
Nick is so used feeling isolated from everyone (with the possible exception of Alan) that he can't understand why anyone would be concerned about him. What shocks him here is the genuine worry that both Mae and Jamie appear to have for him. He's so used to being on his own little island that the idea someone could be interested in his welfare is almost inconceivable.
Quote #8
Nick could have gone in, but he couldn't go in and be one of them. (12.105)
This seems to be the story of Nick's life—even when he's among people, he remains apart.
Quote #9
[Nick] turned away from the ordinary people laughing in the warmth, and wondered if magician's felt this empty and cold all the time. (12.106)
The first part of this quote clearly shows that Nick doesn't consider himself "ordinary." That's not to say that he thinks he's special or places himself above others, though—instead it seems to indicate how aware he is of the fact that he never quite seems to fit in. And the second part of the quote? That seems to show that Nick feel empty and cold—in other words, lonely and isolated. He wants to fit in, but he doesn't know how.