It exists as a concept, but there's no image of it. Funnily, I'm quite strong at maths and can easily reason about things like dependency graphs in my head, bu

It exists as a concept, but there's no image of it. Funnily, I'm quite strong at maths and can easily reason about things like dependency graphs in my head, but I don't need to close my eyes to see it. So I can think and type with my eyes open at the same time :p