While particular improbable events are improbable, the chance of any improbable event happening at all is highly probable.

• Your chances of getting struck by lightning are almost zero. But with so many people walking around and so many storms, it has to happen to someone sooner or later.
• The same is true for clusters of improbable events. The chance of any individual getting struck by lightning more than once is even closer to zero than the chance of it happening once. Yet when we look at all the people in the world, it’s certain to happen to someone.