Hold your breath for a second, and think about your chances of winning the big one in the sweepstakes.
About one in a million, right? That's not very much, but hey, I can spare a few bucks for a
one in a million chance of winning the good life.
Now, consider the same one in a million chance in a different scenario.
Based on the frequency of previous asteroid impacts, the probability of an extinction-level (≥10 km) asteroid impact in this century is around one in 1 million.
Jason G. Matheny, Reducing the Risk of Human Extinction