I think of myself as an exuberant person. I phrase it as "I think of myself as..." because many people have made clear to me that various of the ways I think of myself are wrong in their opinion. Another example, I think of myself as shy. I doubt you could find anyone who knows me in meatspace who would agree, but I think that's because the way I handle my shyness is to act as if I were a confident extrovert. (Unfortunately sometimes my confidence reads as arrogance. Again, so I've been told, by more than one person I trust.)
I'm starting to believe that instead of knowing myself very well, I hardly know myself at all. Do any of us, or do we just tell ourselves a story about who we are? I'm not sure this question is answerable.
It's hard to get good information; people who tell me what they think of me may have any kind of motive, or filter, or not know me very well, so how do I decide their opinion of me is more correct than mine? They are, after all, almost entirely only observing my behavior; the only part of my thoughts they can reach is what I tell them. Not everything I think makes it out into the wild! I'm as hesitant as the next person to admit my worst faults (that is, what I think are my worst faults).
This possibly-unanswerable question is important, though, because I'm trying to make myself a better person, and if I don't have an accurate grasp on my strong and weak points, I might put effort into changing something that doesn't require change. And fail to work on something that is a glaring fault.
The best way I've found so far to handle this is to consider the evidence from other people as well as their opinions. If I have evidence they don't, that might be a good reason to disagree with their conclusions; if they are interpreting the same evidence differently from me, I might change my mind.
But identity...is it only what is expressed? In that case all I am is what others experience of me.
It might be time to read some philosophy.