Lately I've been pre-ocuppied with this question, which frankly makes me look at my surroundings in a fresh way. (I am mainly concerned with objects at the moment, but I think there can be a lot of parallels between objects, and knowledge (about objects))
A related question could be: How do we determine if an object is familiar to us? When we look at an object for the second time, what is it that we see (this time)? Why do we feel at ease in these situations? Can we look at something again, but see it as if we see it for the first time? How does something become unfamiliar to us? What happens when we discover something unknown in the familiar?
I read some about it in the first paragraphs of the second part of Wittgenstein's Brown Book, and am quite fond of his philosophical quietism with its ostensive examples, in a way it seems to be an example in itself these questions, that one only has to look closely at what is so familiar, but at the same time seems to go unnoticed.
I. Do we have a feeling of familiarity whenever we look at familiar objects? Or do we have it usually? When do we actually have it? It helps us to ask: What do we contrast the feeling of familiarity with? One thing we contrast it with is surprise. ... (from L. Wittgenstein, The Blue and Brown Books, p.127)
... and then he goes one to show us examples of situations, and examines them closely.
Heidegger, I believe, also talks about it, but in a different way, in Sense and Time.
I was wondering, would there be other literature that touch upon an aspect of this, which I could read on this subject?