Perceiving an armchair prepares us to sit. Reading the first line in a text prepares us to read it. This article proposes that the affordance construct used to explain reactive potentiation of behavior similarly applies to reactive potentiation of cognitive actions. It defends furthermore that, in both cases, affordance-sensings do not only apply to selective (dis)engagement, but also to the revision and the termination of actions. In the first section, characteristics of environmental affordance-sensings such as directness, stability, action potentiation, valence, (...) and phenomenology are reexamined in light of contemporary cognitive science. In the second section, it is proposed that cognitive affordance-sensings can also be characterized along these dimensions. Called “metacognitive feelings” in the metacognitive literature, their function is to select, engage, revise and post-evaluate cognitive actions. A third section discusses alternative views, and responds to objections. (shrink)