What are your unshakable self-images that you've been conditioned to since childhood/adolescence? Even if you're no longer that way, and you still feel that way...
I'm not a big guy and I've never been a big guy. I was a scrawny kid. Tall among my friends, but scrawny. At 5'10" and 130 lbs, people always called me Skinny. At college, friends teased me all the time for being a stick. Even my girlfriends thought I was so skinny and they all weighed more than I did.
Now that I'm at 167 lbs, I still see myself as the 130-lb boney ass. I would see myself in the mirror and wonder, is that really me? When people say "you look thin" I immediately think they're calling me skinny. I know I'm not a big guy, but I can't shake this "skinny" image.
I also can't shake the feeling that I'm just mediocre in everything. Perhaps I am, but I know I've accomplished many things, too. Still, I've always felt that I'm just mediocre, because that was what people told me when I was a kid. I was nothing special. I was never good enough. If I got a 90, people would say, "Why didn't you get a 100?" There were always kids better than me, and people didn't take me seriously. Even as an adult, I still feel that way. It's one of the hardest self-image to get rid of.