They're not; it's their insecure attachment style (the bond we develop with our first caregivers) to which we are completely oblivious until we start accessing our self-awareness and that psychological education becomes a priority!

For someone who fell for an antagonistic personality, the chances are high one or two of their parents is narcissistic. By narcissistic, I don't only mean NPD; rather a person whose psychological heavy baggage makes them self-absorbed and emotionally unavailable; thus, inadequate for a parenting role, sadly enough...