Skein algebras and skein modules, associated to a 2-manifold or 3-manifold M, have a "dual" meaning in terms of supersymmetric quantum field theory in dimension (6 - dim M). This point of view leads to reinterpretations of various known constructions, e.g. the cluster structure on character varieties, the quantum trace of Bonahon-Wong and its 3-manifold extension due to Panitch-Park / Garoufalidis-Yu, the large center at roots of unity, the WKB analysis of ordinary differential equations. It also suggests new constructions, such as a new approach to conformal blocks for the W_N vertex algebras. I will survey this story, trying to focus on the big picture.