How you view yourself impacts how you act. How you act, influences how you are perceived.
If you don’t think much of yourself, it’ll show up in your posture the way you speak and the kinds of things that you say.
And in turn you may be perceived as quiet, shy, uninterested, someone who doesn’t care. But maybe you have low self-esteem and maybe nobody taught you to think good of yourself.
Perhaps, even though you haven’t yet learnt how to say it or even show it, you actually care quite a lot.