Not entirely -- it's better to think of "unknown unknowns" that current circumstances might well contribute to the probability of occurring. We might know of 10

Not entirely -- it's better to think of "unknown unknowns" that current circumstances might well contribute to the probability of occurring. We might know of 10 events that all "only" have a 1% chance of occurring, causing us to estimate risk of any one occurring at 10%. But because of how much everything is getting mucked with, there might not be 10 events that have a 1% chance, but instead 50, or 100.