  Recent discovery of the fine-grained entropy formula in gravity succeeded in
reconstructing the Page curves that are compatible with unitary evolution. The
formula of generalized entropy derived from the gravitational path integration,
nevertheless, does not provide concrete insight on how the information comes
out from the black hole given that the state of the radiation seems to follow
what was given by Hawking. In this paper, we start from a qubit model and
provide a quantum informational interpretation of entanglement islands and draw
the parallel between the black hole information paradox and the problems of
measurements in quantum mechanics. We show that the Page curve can still be
realized even if information is lost and the information paradox can be
attributed to the measurement problem. We argue that such interpretation is
necessary for a quantum informational model if smooth horizons and bulk
reconstruction are assumed, and show how it explains the Page curves of
solvable models of 2D gravity. Though speculative, the similarities between the
black hole information problem and the measurement problem may suggest some
link in the origins of the two fundamental issues of distant fields.
