The first impression is everything and you only get one chance to introduce yourself. So, learn the science of first impressions to make yours count.
It takes just a glance, probably 3 seconds for someone to rate you when you meet for the first time. In this short time, others make comments and form an opinion about you based on your appearance, body language, behavior, attitude, manners, and attire.
With each new encounter, you are assessed and your further impression is created. These first impressions are almost impossible to reverse or undo, and often set the tone of subsequent relationships.