If you would like to learn more about timelines, I suggest that you look into the work of Starfire Tor.  Her work has clarified a lot for me.  It’s surprising that I hadn’t heard of her before a few months ago.  She has been studying timelines and the causes of shifts for many years.  Her discovery of “Time Shifts” and “The Time Shift Living Dead” was hijacked, corrupted, and re-titled the Mandela Effect.  The evidence is overwhelming.  Her name for this phenomenon is The Time Shift Living Dead, and she would prefer that you use that name for it.  She explains the reason for that in the video below.  I have not personally discovered any Time Shift Living Dead situations, but I have stumbled onto other rather mundane evidence of time shifts that I have described in this blog.  They’re found in My Best Stories.  Where my exploration of time shifts has been casual, hers has been scientific.  Starfire Tor discusses the topic of Time Shift Living Dead in the following episode of The Time Chronicles with Karen Ellington.