  Almost all of the entropy in the universe is in the form of
Bekenstein--Hawking (BH) entropy of super-massive black holes. This entropy, if
it satisfies Boltzmann's equation $S=\log{\cal N}$, hence represents almost all
the accessible phase space of the Universe, somehow associated to objects which
themselves fill out a very small fraction of ordinary three-dimensional space.
Although time scales are very long, it is believed that black holes will
eventually evaporate by emitting Hawking radiation, which is thermal when
counted mode by mode. A pure quantum state collapsing to a black hole will
hence eventually re-emerge as a state with strictly positive entropy, which
constitutes the famous black hole information paradox. Expanding on a remark by
Hawking we posit that BH entropy is a thermodynamic entropy, which must be
distinguished from information-theoretic entropy. The paradox can then be
explained by information return in Hawking radiation. The novel perspective
advanced here is that if BH entropy counts the number of accessible physical
states in a quantum black hole, then the paradox can be seen as an instance of
the fundamental problem of statistical mechanics. We suggest a specific analogy
to the increase of the entropy in a solvation process. We further show that the
huge phase volume (${\cal N}$), which must be made available to the universe in
a gravitational collapse, cannot originate from the entanglement between
ordinary matter and/or radiation inside and outside the black hole. We argue
that, instead, the quantum degrees of freedom of the gravitational field must
get activated near the singularity, resulting in a final state of the
`entangled entanglement' form involving both matter and gravity.
