A heuristic analysis of correspondence between classical and quantum mechanics for the class of dynamical models where quantization requires the use of a non-standard scalar product. In a way supported by an explicitly solvable illustrative example the author emphasizes the important role of semi-classical analysis in a systematic clarification of the puzzles presented by the so called PT-symmetric potentials which are complex but which are able to generate bound states with real energies in a certain domain of parameters. The text summarizes the talk presented during the 3rd International Workshop ``Pseudo-Hermitian Hamiltonians in Quantum Physics" (Istanbul, Turkey, June 2005). MR2230233 Ahmed, Zafar Phase space trajectories and quantization in PT-symmetric quantum mechanics. Czechoslovak J. Phys. 55 (2005), no. 9, 1055--1062. 81Q10