The Sagittarius arm is where those suffering from the "Mandela Effect" are from. Their almost identical earth is on this arm in the galaxy but contains minor and major differences in everything from geography which differs only slightly and bible verses which are different as well as movies and names. The reason this has happened is unknown. There could be a multiverse of other earths dotted around the Milky Way and these people have been placed into this reality for some reason. These people are not mad, They truly believe this has happened and who's to say it hasn't. If it has happened to them, well it could happen to anyone. Perhaps we should no longer look for alien life but identical life in other parts in the galaxy.
See evidence in the Another World gallery