I learned of the Mandela effect in about 2016, tbh none of it really interested me because it seemed concentrated on American stuff, that wasn't familiar in the first place. I did experience a flip flop a short time after, the film with Tom hanks where he says "Houston we have a problem" had changed to "Houston we've had a problem" there were YouTube vids about this, the next time I encountered this, apparently it had always been "Houston we have a problem"  think this is a very common thing.
Anyway, there was a silence of the lambs Mandela where hannibal never said "hello clarice" fair enough. However shortly before I got rid of sky tv it was really late at night and I was watching sky on the player that you could use on your pc. It was really clunky to use tbh and I would imagine not very popular due to this, you couldn't record or rewind on it, not sure if it still exists. I was watching an old episode of gogglebox and they happened to watch silence of the lambs, however it was the "old" version where he did say "hello clarice" 
I was so confused I watched the film, which was the new version. However I happened to bump into the same episode of gogglebox a week later (but with the signing lady in the corner) and it had changed to the new version, tbh the whole of the gogglebox ep seemed different, more HD. Wtaf.
It still does my nut in, I don't understand.