Hazarding a guess: A frequent theme in bullying (at least in my experience) is falsely building up an expectation of positive outcome, then pulling out the rug, while blaming the victim for having unrealistic expectations, usually with rhetoric that they are inherently unworthy of positive outcomes, so by deceiving themselves they have only revealed their compounded lack of worth.

Experience that enough and I would expect one could develop quite advanced heuristics to protect oneself from deception.