Full Idea
I don't agree that the mark of knowledge is justification, first because justification isn't sufficient - your true opinion that you will lose the lottery isn't knowledge, whatever the odds; and also not necessary - for what supports perception or memory?
Gist of Idea
Justification is neither sufficient nor necessary for knowledge
Source
David Lewis (Elusive Knowledge [1996])
Book Reference
Lewis,David: 'Papers in Metaphysics and Epistemology' [CUP 1999], p.421
A Reaction
I don't think I agree. The point about the lottery is that an overwhelming reason will never get you to knowing that you won't win. But good reasons are coherent, not statistical. If perceptions are dubious, justification must be available.