About your question, I think my answer is that confidence is most important in internship hunting.
In us. Especially in America. I found that American people really good at sell themselves. They might say they know the stuff really well when they only understand half of them. They might tell the interviewers that their GPA is not good because they are just not good at taking exams: they learn the stuff very well, they know this, they know that, blahblahblah....
But in fact, they know nothing!
So I think confidence is vitally important here.
Everyone has to know how to sell yourself, emphasize what you know and tell people how excellent you are. Don&`&t be shy. Always ask why reject me.
I wrote a quite serious letter to the recruiter in Towers Perrin to ask why they didn&`&t even give me a chance to interview. (They offered a lot of students in GSU to interview.)
Surprisingly, I got replied. They told me which points of me they appreciate and which point was the reason for which they made the decision. I have to say that their advices are really helpful.