Yes, it's troubling to me, though I try not to let it get to me. I wonder how much of what I think I remember is actually different now but too far in the past for me to notice unless I hunt for it.

Like the TV show 'Everwood' totally disappeared from existence for me at some point. I could remember it, I knew the cast, I'd watched it all, yet it was gone from existence. But it's like remembering it and searching for it triggered some system that went, 'Oh shit, we have to write that back into her reality, she's remembered it,' and a couple weeks later when I checked again, Everwood is back to being a TV show that has always existed exactly as I remembered it.

I wonder if it's the same with older media. Maybe I shifted to this dimension for some reason, and it happens to be one where an old song came out a year earlier. That's not a big deal to the system unless I happen to go looking for that old forgotten song, then suddenly the imperfection of the system is revealed, but having seen it, it's too late for the system to shift again to hide the change.

It's weird shit, it'd be enough to drive someone mad if they focused on it too much.