Apparently there aren't many: no one (except perhaps a few buddhists who spent an unreasonable amount of time meditating) noticed until now. The interesting bit is that we don't notice.
The finding highlights and perhaps provides somewhat of a meaningful answer to philosophical arguments around what we perceive to be reality around us in fact being very much an illusion of continuity. The fact that we so readily trick ourselves into believing, and only through intense mindfulness/introspection are we able to contradict that sense of internal consistency, is quite profound in my opinion.
For folks who are trying to be more focused, it seems like this emphasises the importance of training yourself to re-focus your attention