Your optimistic nature cannot have that large an effect on the world; it cannot, of itself, decrease the probability of nuclear war by 20%, or however much your optimistic nature shifted your beliefs. Shifting your beliefs by a large amount, due to an event that only slightly increases your chance of being right, will still mess up your mapping.
I only need to assume that everybody else or, at least, many other people are similarly irrationally optimistic as I and then the effect of optimism on the world could well be significant and make a 20% change? The assumption is not at all far fetched.
Your optimistic nature cannot have that large an effect on the world; it cannot, of itself, decrease the probability of nuclear war by 20%, or however much your optimistic nature shifted your beliefs. Shifting your beliefs by a large amount, due to an event that only slightly increases your chance of being right, will still mess up your mapping.
I only need to assume that everybody else or, at least, many other people are similarly irrationally optimistic as I and then the effect of optimism on the world could well be significant and make a 20% change? The assumption is not at all far fetched.