  Systems of enhanced memory capacity are subjected to a universal effect of
memory burden, which suppresses their decay. In this paper, we study a
prototype model to show that memory burden can be overcome by rewriting stored
quantum information from one set of degrees of freedom to another one. However,
due to a suppressed rate of rewriting, the evolution becomes extremely slow
compared to the initial stage. Applied to black holes, this predicts a
metamorphosis, including a drastic deviation from Hawking evaporation, at the
latest after losing half of the mass. This raises a tantalizing question about
the fate of a black hole. As two likely options, it can either become extremely
long lived or decay via a new classical instability into gravitational lumps.
The first option would open up a new window for small primordial black holes as
viable dark matter candidates.
