Rather than that classic but potentially devastating misconception of "They're talking to me an awful lot, could they be interested in me?" he's been leaning more towards "She's just talking to me at all because she's the class rep and I'm a loner." Which is a healthy mindset to take in comparison to the other take, never be so full of yourself that you think any and every interaction with someone is more than it might be. However, in this case he's only about half right and he's gone so far in the other direction that it's just as much of a problem. She is the very responsible class rep type of person, but she also does clearly hold special attention toward him specifically... he just has his blinders on toward that, like a self defense mechanism.