My explanation is perhaps bad statistical reasoning. You never really know what time you would have woken up naturally without the alarm. So those instances get

My explanation is perhaps bad statistical reasoning. You never really know what time you would have woken up naturally without the alarm. So those instances get forgotten. All that you think about are the times when you get up right before the alarm. And I suspect people are usually are not within a minute, but more like 10-20 minutes.