  Mysterious Fast Radio Bursts (FRB), still eluding a rational explanation, are
astronomical radio flashes with durations of milliseconds. They are thought to
be of an extragalactic origin, with luminosities orders of magnitude larger
than any known short timescale radio transients. Numerous models have been
proposed in order to explain these powerful and brief outbursts but none of
them is commonly accepted, it is not clear which of these scenarios might
account for real FRB. The crucial question that remains unanswered is: what
makes FRB so exceptionally powerful and so exceptionally rare?! If the bursts
are related with something happening with a star-scale object and its immediate
neighborhood, why all detected FRB events take place in very distant galaxies
and not in our own galaxy!? In this paper we argue that the non-linear
phenomenon - self-trapping - which may provide efficient but rarely occurring
beaming of radio emission towards an observer, coupled with another, also rare
but powerful phenomenon providing the initial radio emission, may account for
the ultra-rare appearance of FRB.
