I find this really interesting. I have a few, both “mine” and about me.
I have a really strong memory of watching a particular TV event in my grandmother’s house. I can picture exactly where I was, sitting on the carpet in her living room, with dad and gran also there. It is so vivid and feels real, except, gran moved into sheltered housing 3 years before this event took place. It is possible that I still watched the event with her and my brain has transposed the setting, or maybe she wasn’t there at all. Very odd.
When I was younger, I was part of a group of 5 friends who went out together every Saturday night without fail. There was a bit of a disagreement at one point which led to two of the group going on holiday together which pissed off the rest of us so we decided to have a really epic night out without them. During this night out an incredibly specific thing happened to me as a result of mistaken identity (a very funny thing, not traumatic as I realise this might imply). Our friendship group got back together and this story has been told many times, except now one of the two who was on holiday is convinced that not only were we all there when it happened, but that the incident actually happened to her. Even now, 25 years on, most of us are still in contact and she tells this story regularly to others – her dad even told the story during his father-of-the-bride speech at her wedding and it has passed into legend amongst her friends and family. I would doubt myself but the other two friends who were actually on the night out agree with me that she wasn’t even in the country at the time and that the incident happened to me but it has gone on for so long that we all now just agree with her. I genuinely don’t think she “stole” the story in a malicious way. She really seems to believe without a doubt that this thing happened to her.
On the subject of weddings, a few friends and I share a memory of a mutual friend lusting after the bridesmaid and making a fool of himself at another friends wedding. Said friend was in Australia at the time. it's strange that we all share the same memory but I assume that we must have said something at the time like "if Dave were here he'd be trying to chat her up" and it has stuck with all of us.
On a different note – I’ve written about this one on MN before – my entire family have a false belief that I screwed up my uni degree and/or dropped out. I studied Modern Languages and this included a year abroad. I was very nervous going to make a temporary life in a new country where I knew no-one and it is true that in the first couple of weeks I was quite homesick and dealing with culture shock and I cried on the phone to my mum a few times. A couple of years before I did my year abroad, the daughter of my parents’ friends had done similar and couldn’t settle in the country at all, to the point where she had a breakdown and the parents had to fly across to physically bring her home. I know my mum was worried about the same thing happening to me but thing did start falling into place for me, I made friends and grew to feel completely at home in this other country and city, so much so that I considered dropping out of uni to stay there permanently. Eventually I was persuaded by my tutors to take an interruption of study for a year, thus extending my stay to two years but then coming back to do the final year. I did this and had plans to then return to the other country to live and work after graduation but, having now ended up in a new uni cohort, I ended up meeting my now-DH and decided to stay in the UK with him after graduating – although we have always visited my “second home” regularly because I still have a deep love for the place. This reality has been twisted in the heads of my parents and siblings (I genuinely don’t know where it started but the belief has spread and taken hold like a weed) and more distant family members so people think various combinations of the following (a) hated my time abroad and cut it short because I was homesick, (b) dropped out of uni – with a follow on false memory that I was struggling and the year abroad proved to me that I couldn’t speak the language very well, (c) returned to uni but failed my finals (I got a 2:1). No matter how many times I point out that my stay was extended and question why I would keep going back to that place, they are adamant that I screwed up my year abroad and then the rest of my degree. They've obviously confused what happened to the friend, plus the fact that I considered dropping out AND then the fact that I didn't return as planned but they are so sure of their version of events that it has now become the family's shameful secret and I'm constantly being told not to worry about happened in the past and at least I tried....