  Recently a certain conceptual puzzle in the AdS/CFT correspondence,
concerning the growth of quantum circuit complexity and the wormhole volume,
has been identified by Bouland-Fefferman-Vazirani and Susskind. In this note,
we propose a resolution of the puzzle and save the quantum Extended
Church-Turing thesis by arguing that there is no computational shortcut in
measuring the volume due to gravitational backreaction from bulk observers. A
certain strengthening of the firewall puzzle from the computational complexity
perspective, as well as its potential resolution, is also presented.
