Usually when I think I'm realizing what other people think of me, it's really just me thinking about what I think other people are thinking about me. So it's really me thinking things about me that I would rather not think. If you get my meaning.
There was an old Zen clique (sp?) I read somewhere in which it was suggested that you consider other people as though they were wooden puppets. I guess that means to not get too hung up on what their motivations are (they probably don't know), but watch their behaviors closely 'cause they are real.
Personally, I think you need at LEAST one person whose opinion of you means almost everything to you. The word that describes people who don't have at least one such person (or animal for that matter) in front of whom they could feel (really feel) ashamed is sociopath. I prefer the older, more prejorative term, psychopath. The new DSMIV version--Anitisocial Personality Disorder does not do justice to just how truly evil some people can be. For a good psychological AND spiritual analysis of the nature of evil, check out Scott Peck's lesser known work, People of the Lie. In it he hypothesizes that the nature of evil is the refusal to see yourself honestly. The best and most entertaining descriptions of psychopaths (outside of Thomas Harris novels) are found in Hervey Cleckley's classic, The Mask of Sanity (I think I got the name right). He was also one of the co-authors of The Three Faces of Eve. In Mask he hypothesizes that psychopaths and part-psychopaths (see William Jefferson Clinton) lack a crucial part of the sense of empathy. They know (learn) what is wrong intellectually, but never truly sense another's pain as if it were their own (if I remember right).