  On the occasion of this ArkadyFest, celebrating Arkady Vainshtein's 60th
birthday, I review some selected aspects of the connection between perturbative
and nonperturbative physics, a subject to which Arkady has made many important
contributions. I first review this connection in quantum mechanics, which was
the subject of Arkady's very first paper. Then I discuss this issue in relation
to effective actions in field theory, which also touches on Arkady's work on
operator product expansions. Finally, I conclude with a discussion of a special
quantum mechanical system, a quasi-exactly solvable model with
energy-reflection duality, which exhibits an explicit duality between the
perturbative and nonperturbative sectors, without invoking supersymmetry.
