Well it happens (possibly) twice every lifetime. The next time after tuesday/wednesday this week will be in 2117.

And since an "overnight success" take about ten years, there should be 20 "once in a lifetime" events for every "overnight success".

Each type is on a different schedule.

Every week you can once (or less) in a lifetime lottery numbers, too.

Improbable things happen pretty often in the universe :)