How human beings come to think in new narratives is a wonderful topic. As much as how people attach to some frame or some narrative.

I have more or less an idea about how people attach and dettach, accpet and reject frames...about how each one constructs his own personal narrative but there are only partial rules. Each person is a different world engaged inthsoe rules. And I deeply believe that the process is chaotic and deterministic with not that much random noise (I have no proof wahtsoever but I will bet that most physicist agree with me, when we are explained cahotic system with noise we all come to the same conclusion.. this is how I came to be). We do have some indication coming from the excellent predictions socioologists and antrhopologists do predicting human behaviour in a lot of circumstances at short-term scales

But regarding how human beigns develop personal and different narratives, some of them as powerfull as gandhi, well it is a biological and cultural aptitude, like maths. You develop them by training, and the more you train the more you develop teh aptittue.. and may be you may need some brain structure working very well (thanks to some biological properties.. ei maybe encoding genes and proteins may have a small role in it by a cascade effect). It might involve reflexion, stroy-telling and other brain enhanced activities (self-inspection and so on), who really knows je jej certianly I do not know. Add probably it can not be known scientifically... I guess  the answer must go to the wonderful magic box for now :)

A pleasure

I therefore claim to show, not how men think in myths, but how myths operate in men's minds without their being aware of the fact. Levi-Strauss, Claude