Most of us can not see ourselves as others do. We think we have an idea, but its accuracy is an illusion. How we perceive how others perceive us is called "metaperception." Studies show we often view ourselves more favorably than others do. It's not wishful thinking, it has a lot to do with our need to be accepted, liked, and connected. A positive self-concept is beneficial.
More information on metaperceptions can be found here.