Relationship Confusion And Heartbreak

Cognitive dissonance can be created in our own minds when we meet someone who seems very straightforward and reliable to us, but who's actions are actually unreliable.
The impression we have of them in our minds is "Person who will keep their agreements, person who stands up for what's right, person who will treat me with true reciprocal respect, person who I can depend on who will not betray or hurt me."
So when this person does not live up to the impression we have of them in our minds, it can cause confusion, anxiety, sadness, pain, and heartbreak. If their behavior is abusive, it can cause trauma.
We expect one thing, but we are experiencing another. Like biting into an apple that tastes like a hot dog. Even if we like hot dogs, we would immediately spit out an apple that tasted like one.
There are different causes for this issue. One of them could be our own deep desire to find someone to trust, so we may pin that profile onto someone we don't know very well at all. That person may remind us for some reason of a person we trusted in our past, so we subconsciously assume they have similar personality traits, or will treat us the same way the other person did. We may simply not be very good at reading people. We may be star-struck or love-struck and ignore the person's real behavior that we would have noticed otherwise.
If we have a disorder ourselves, or just a lack of maturity, we may have unrealistic expectations of the other person that they couldn't possibly live up to, and that we ourselves could not live up to. We may feel rejected and betrayed at their normal human behavior, and even misinterpret their words, emotional expression, and actions. We may see their sadness as an expression of anger or judgment toward us, for example. We may interpret their anger as abusive rage, we may interpret their happiness as smugness, etc.
If the other person has a disorder or is very immature, they may have purposely created an impression of themselves that does not represent their real personality or intentions. Con artists do this on a regular basis. Their goal could be anything, from getting their hands on something we own, to getting us to become subservient to them. In order to get us to trust them, they create a false "Good Person" image of themselves, which is often actually an AMPLIFIED "Good Person" image; a con artist can not afford to risk us seeing through their facade, so we may actually buy into their "Good Person" image MORE than an ACTUAL Good Person, because a genuinely good person does not try to create an image, and all their "flaws" show. Many people actually fall for con-artists and reject genuinely good people for this reason.
Con artists are not the only ones who create a "Good Person" image, however. Many people grew up in cultures in which they may have been punished, picked on or ostracized if they did not learn how to create a false image of themselves to "wear" in front of others. If a child has no adults who see them for who they really are, who listens to them without shaming them or invalidating them, who disciplines them without anger or agenda, who teaches them how to stand up for themselves or for what is right,who gives them safe sanctuary, or who teaches them why ethics and values are so important, then the child may easily resort to simply mimicking what a "good person" LOOKS LIKE without having an understanding of the underlying reasons, feelings, and dynamics. Mimicking the superficial behaviors of others who are respected in the family and community can gain them acceptance and respect. However, the behavior they are mimicking is only surface behavior, like vocal tone, language, clothing, facial expression, body posturing and compliment giving, or minimal "reliable person" actions such as showing up on time, showing up at key events, or making a show of occasionally helping others. Behind the scenes, their intentions, emotions, and motives are that of the child they were who did not receive enough guidance and security from the adults in their life. (Sometimes even a strong parent is unable to provide enough guidance and security to a child, due to other people or circumstances.)
So, when our impression of a person is one thing, but their actions do not match this impression, we can experience real emotional and cognitive dissonance. We can experience sadness, heartbreak, confusion, and pain. What we can do is step back and reevaluate our impression of the person, and discover objectively (which can be very difficult for most of us) where this false impression really came from. Are our own expectations too high? Are we looking for a "Super-Good" person who would not really exist in reality? Did we simply not give ourselves enough time to get to know the person, and paint our own picture of them from our imagination? Or did this person purposely and continually try to create a false image to make us believe and trust them?