"Previous studies have disagreed on whether or not weaker memories are stabilized, or made easier to recall, by attachment to a more prominent one."
So doesn't seem that obvious at all.
I remember random mundane events from tons of random days, unconnected to any prominent event (as near as I can determine anyway). And I also remember some random mundane stuff from days something prominent did happen. Whether there's a bias towards days with prominent events is entirely unclear to me.