When we are acting, some of our knowledge is active. We might think of this as comparable to the execution of a program. When we perceive, there is also active knowledge, processing the data that flows in from our senses. In thought, there is also active knowledge. Believing means to give control to some body of knowledge, to execute it. (See also https://creativisticphilosophy.wordpress.com/2013/04/28/active-information/)
We construct things out of the raw sense data by the activity of chunks of knowledge. There is a world that exists independently of us, but we produce or project some world out of it by the activity of our active knowledge. (See also https://creativisticphilosophy.wordpress.com/2014/07/02/generating-objects-towards-a-procedural-ontology/)
We can think of this perceived or projected reality as a set of as-if-constructions. Each as-if-construction is projected by a chunk of knowledge (part of which might be procedural) that is active. You enter an as-if-construction by activating that knowledge; you step out of it by deactivating the corresponding knowledge.
The term “knowledge” here is not used in the way it is used in traditional epistemology (as “justified true belief”) but instead meaning information that has become active, i.e. that influences the way other information is processed or the way you act. You may think of it as something analogous to a program. Knowledge is used information. Declarative, propositional knowledge is only a fraction of it, and by limiting its view to this subset of knowledge and the question of its truth, traditional epistemology has been limiting itself (one may view traditional epistemology as an as-if-construction: philosophers act as if all knowledge consisted of propositions which are built up from concepts, and all thinking processes consist of logical inferences; other forms of knowledge and of cognitive processes are masked).