It would take a while to come up with all the examples I could think of, but here’s a few I can remember off the top of my head.
A friend insisting the Thrawn trilogy was truly the basis for the ST movies, couldn’t get him to shut up till the SECOND trailer for TFA.
Numerous people insisting the OT stormtroopers were still clones of Jango Fett. Ugh, that one just got me so infuriated, especially given they were all people who put the PT above the OT, so I was already arguing with wackos.
Not kidding, people insisting that the 2004 SE’s are the original theatrical versions. I show them something from the original, and they’re like “why did they get rid of Jabba, why did they cut out the wampa, where’s that funny song with screaming cockroach guy”.