In a job interview, the interviewees get dressed in suits. It's because they want to leave good impressions. I think first impression matters in some rate. However, if the first impression makes people lose interest in that person and stop them from learning more about him/her, what a shame! I believe first impression shouldn't keep a person from knowing them. But of course, leaving good first impression is showing people good manner too. Therefore, I think people should care about their first impressions but first impressions should not be permanent.