There is a reason personality tests keep drawing people. We understand ourselves as stories.
Asked what kind of person they are, people tell a story rather than list traits: this happened, and so I became this way. Weaving a life into a single narrative appears to be the basic way we understand ourselves, because scattered events become manageable once they have a plot.
Memory is not stored like recorded video; it is reconstructed each time it is retrieved. So the same past event can be remembered differently depending on who you currently take yourself to be. People who feel their personality changed tend to remember their past selves as also having been different. This is not lying; it is how memory works.
Personality tests and type results supply material for building that story. They give you words for yourself, gather scattered experiences under one explanation, and produce a form you can pass on to others. People keep taking them because of that function rather than because the results are accurate. Knowing the structure lets you read a result page differently.
Once a self-story sets, facts that do not fit stop registering. The sentence 'that is just how I am' is an explanation and a constraint at once. People in fact behave quite differently across situations, and a hardened story files those variations as exceptions. Deliberately recalling counter-examples is enough to open it up again.
That the story is not fixed is less a burden than room to move. The same events can be woven as evidence of failure or as a process of learning. This does not mean distorting facts; it means the same facts admit more than one reading. A considerable part of what therapy does relates to this rewriting.
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