  Non-deterministic giant waves, denoted as rogue, killer, monster or freak
waves, have been reported in many different branches of physics. Their origin
is however still unknown: despite the massive numerical and experimental
evidence, the ultimate reason for their spontaneous formation has not been
identified yet. Here we show that rogue waves in optical fibres actually result
from a complex dynamic process very similar to well known mechanisms such as
glass transitions and protein folding. We describe how the interaction among
optical solitons produces an energy landscape in a highly-dimensional parameter
space with multiple quasi-equilibrium points. These configurations have the
same statistical distribution of the observed rogue events and are explored
during the light dynamics due to soliton collisions, with inelastic mechanisms
enhancing the process. Slightly different initial conditions lead to very
different dynamics in this complex geometry; a rogue soliton turns out to stem
from one particular deep quasi-equilibrium point of the energy landscape in
which the system may be transiently trapped during evolution. This explanation
will prove fruitful to the wide community interested in freak waves.
