A personal Mandela Effect years before the term arose?

Did Robert Smith experience a personal Mandela Effect when he wrote 'Friday I'm in love' without realising it? The story is he was certain the tune was copied from somewhere, so played it to everyone he knew who all told him it wasn't. Only when convinced he really was the first person to write it was it released as a single, and it became one of his band, The Cure's, biggest hits.

This isn't being classed as a Mandela Effect because it's clear only one person was affected by it, if at all, but this pattern regarding music isn't actually unique.

There are crazy stories of band members hearing a track on the radio and thinking someone "ripped them off", i.e. copied their style, only to be told it was them all along. I'm looking at you, Steven Tyler of Aerosmith. Some go even further, with David Bowie allegedly forgetting he recorded an entire album. Both later put these episodes down do health and medicinal related issues.

Familiar tunes

We all get tunes stuck in our heads - these are affectionately known as earworms. Most of the time, you know exactly what the song is, but it is extremely annoying when you have the tune, but don't know where it's from. That's the opposite of Smith and Friday I'm in love. This happened to one guy who went to extreme lengths to resolve it's origin.

Technology can help. There are smartphone apps which lets you hum the tune, check it's database, then report back what it is. A great example of this is SoundHound. If only Robert Smith has this back in 1992.

In a way, all odd human memory related issues have a connection to the Mandela Effect, even if it's a reverse one such as this. And of course, the hardcore believers might well argue Smith came from a universe where it was already a huge hit ;-)