People with healthy egos are able to register that someone does not want them as a romantic partner without having a crisis, yes.
I see I’ve upset some users today. This may seem like stating the obvious but clearly some people here need to hear it:
If you are emotionally devastated by rejection you likely do not have a healthy ego or self-image. This is the confidence part.
Assigning responsibility for fixing your self-image to a potential romantic partner is seeking external validation for an internal problem.
No amount of external validation will fix you. It will only feed the unhealthy expectations you’re already acting on.
Confidence is the external display of a healthy self-image (overconfidence is another example of external display of an unhealthy self-image).
Potential partners can sense your desperation for validation and it is not an attractive personality trait. It’s basically saying “I need you to do this emotional labor for me because I am not strong enough”.