intimidated?

I joined a new gym a few months back and he's a trainer there. It's obvious he's interested in me but quite shy. Everytime I see him, he would come and talk to me all the time. One time he asked what my most and least faborite colors were and unfortunately my least favortie color was the one he was wearing. So he let it slip that he would have to change it so I would go out with him.

However, recently he's just learned about my education backgroud and work-related stuff. He said he was impressed, but noticeably fell silent. He told me he was only a high school dropout while I'm doing my Ph.D and have a high paying job. After that day he talks to me less and less.

Why do you think that is? Is it possible that he might be intimidated by my profile? I mean I heard about this intimidation stuff like a thousand times, but it has never been a problem because I really like him. He's really hot.