Yep. I agree. Even the most apparently confident person has something about themselves they are uncomfortable with. If they don't, they might be a psychopath. But as unsprung says, it is many times just in our heads and other people don't even notice or care. Confidence truly is irresistible and makes our physical weaknesses and faults seem less important - and I believe even sometimes make them appealing. I have a friend who is very scrawny, but he is confident, smart as hell, and not afraid to tell anyone what he thinks. His confidence makes him seem larger than he is and people respect him a great deal. The problem is that we often let our physical issues overwhelm us to the point of defining us, which erodes our confidence making the matter even worse.
"No beast so fierce but knows some touch of pity."
"But I know none, and therefore am no beast."
- Shakespeare, Richard III