My son's ribcage is uneven and when he was a baby (a skinny little peanut so it was really noticeable!) I was terrified it meant something was wrong. The doctor assured me it was common, just more pronounced in some people than in others.
My left ribcage also sticks out more than my right! It's been bugging me for a while, as it is very obvious no matter if I'm standing up or lying down. All this time, I thought I was a weirdo. Glad to know that there are other people like me.
It is normal. Just like how our face is different on one side to the other. (Use a mirror, and use it to split your face in half...and compare the images of one side of your face w/ the other. You'll see the difference). One side of your body is more dominant than the other.
In advanced sports medicine, it can be quite detailed...looking at issues such as your posture, bone structure, etc. Very fascinating to hear about this stuff...at least for me...
Mine sticks out too! And it's the left side, it's more sensitive too, and hurts at times but the doctor said it was just uneven and nothing wrong with it because my back was fine. It always bugged me because I noticed it after I had surgery for a ruptured appendix. It's probably been like that though for a while. Glad to hear I'm not the only one with uneven ribs! YAY!