For example, I was certain that I started with "Red Box" D&D. That box art is so iconic and so much of D&D culture discussion and songs reference Red Box D&D. But then I read that Red Box didn't come with a module. And if there is one thing I am
sure about is that my first box set came with Keep on the Borderlands. Because I kept playing it over and over when I first got the game, because that is what I thought the game was.
But then...the only gaming artifact I still have from those days is a single dog-chewn d10. It is pale blue with the white-crayon filled numbers. But when I look on-line, I see blue dice with the Mentzer box and Yellow dice with the Moldvay box. I'm certain that Keep on the Borderlands was in my boxed set and I highly doubt my parents would have thought to buy the module separately. But who knows. I can't trust my memory and my parents don't remember. Maybe different printings had different colored dice.
I talk to friends of my mine that I played with back in the 80s and they'll remember games and adventures that I have no recollection of.
So, while I cherish my memories of gaming in the 80s, I certainly don't trust them entirely.