Answer:
Self-concept, also know as self-perception, self-identity, perspective...
Step-by-step explanation:
A self-concept refers to all concepts about oneself, it's how we perceive ourselves. However, self-concept is not the same as self-esteem, which is an evaluation and opinion, for example, a self-concept could be "I'm good in mathematics", and a self-esteem could be "I feel good and satisfy by being good at mathematics". Another concept is self-awareness, which is also different, because it's the ability of introspection, being aware of ourselves, attitudes and behaviours.
Specifically, self-concept is a higher level concept because requires the interaction between self-esteem, self-awareness or self-knowledge, all these form the self-concept, the question Who am I?
Therefore, self-concept is what better fits to complete the statement, because it's about one's perception, which is a whole perspective of oneself.