  From the principle that there is no absolute description of a physical state,
we advance the approach according to which one should be able to describe the
physics from the perspective of a quantum particle. The kinematics seen from
this frame of reference is shown to be rather unconventional. In particular, we
discuss several subtleties emerging in the relative formulation of central
notions such as vector states, the classical limit, entanglement, uncertainty
relations, and the complementary principle. A Hamiltonian formulation is
derived as well which correctly encapsulates effects of fictitious forces
associated with the accelerated motion of the frame. Our approach shows,
therefore, how to formulate nonrelativistic quantum mechanics within
noninertial reference frames which can be consistently described by the theory,
with no appeal to classical elements.
