In absolutely every and any case of otherkinness, there exists a possibility that they are simply mistaken. They saw something, felt something, thought something, remembered something and attributed it to being kin, and they were simply wrong. It had some other explanation, or was misattributed. They didn't think it due to glitz, glamour, delusion, disorder, or so on; they just made a godshonest mistake.

On a related note: sometimes one mistakes oneself for one kintype and figures out later that it was another, perhaps remotely related, kintype. The person who thinks they're a demon only to find out later that they were a gargoyle -- a very similar looking creature. A unicorn who suddenly realizes with a startling gasp that they had wings AND a horn. A person who thinks they were an elf for a long time, only to eventually realize that they were an angelic.