Do you think there exists a person who never has any low self-esteem/confidence moments?

I ask this as a person with an unusually high self-esteem and confidence.

Of course, this potential someone has to be mentally sane.

I just wonder in the sense of, if so many people act as if they have high self-esteem and confidence even while they don't, how can we be so sure that not ever having bad moments in this domain is possible?