I completely agree there is a difference between remembering and then referencing something interesting, and understanding something. For me when I understand something it fits into my internal structures of ‘knowing’. If it sits comfortably in my structures, it builds as part of my understanding like it’s part of me. If it doesn’t sit comfortably - it’s eventually rejected if I can’t bridge it in. When it doesn’t fit into my trusted understanding or experienced understanding I don’t ‘know it’. So if I read something interesting but it doesn’t become part of me I don’t know it. I don’t think we value this knowledge enough, the knowledge that is living inside.