My thoughts are that the facts don't matter. Even in the real world, people hold beliefs that are largely irrelevant to the facts. For stuff like being drunk or having dreams, your memory of them tends to be even worse rest in other scenarios. It's hard to form a solid belief around something so unclear. It's much easier to form a belief around a clearly remembered falsehood. I find it similar to how friendships are formed - it's less about what you have in common and more about shared context. Clear memory of that context is a prerequisite.