Why does my professor treats me differently?

I mean it's like he has a double standard. He helps every student in cl with their projects, and gives lots of feedback to improve expect me even when I'm stuck in my project. He answers other students emails as soon as he gets them but when I send one he ignores it sometimes for days. It's not like he thinks i'm retarded cuz I got the highest grade in the first midterm and quizzes, and I'm very quiet in cl. Why does he do that?