In this essay, I would like to write a little about first impressions and if I agree with the title statement.   

Part of what differentiates humans from other animals is the ability to think rationally, even though their emotional side has not been concealed. It is quite the opposite, the emotional part present in each human is heavily present, they influence how humans make decisions, they are given names - gut feeling, sixth sense, have a feeling- but should people trust that much on their irrational judgment? 
First impressions are examples of this type of judgment. The belief that what one makes of somebody at first can tell basically everything about that new person and is always right. In my own experience, I have had occasions where that first impression proved to be true and I could not shake the feeling that I already knew about it, no doubt. However, there were also instances where I found out later that that first impression was wrong when my first thought about someone was not good and now they are people very near and dear to my heart. 
Having only a first impression in mind, it's too early to state a hundred percent sure that you know that person.  To say those impressions are always right is to put human and human relationships as a very simple portion of our lives when clearly it is not. People should trust themselves and in their feeling, but also keeping an open-minded because there is always a chance that they are wrong.