BlackoutCreature2 wrote: I don't know if that has to do with episode quality or if I'm just getting old.
Sheer volume. No one can clearly remember and recall 500+ different episodes of a franchise they only binged once 10 years ago. You'll remember the highlights but not nearly all of it.
Even a single standalone movie you can watch once and then forget a lot of the details in the course of a year... and yet be reminded when watching it again.
I'm going through the various series now with my wife (who has not seen most of them) and I know I've seen all of them... but if it's not an episode Chuck has reviewed then I maybe haven't thought about or seen the episode in a decade and might not really recall where it's going. there's quite a lot of episodes where I remember once scene or moment or a costume, and very little else.
This is especially true with me and classic Doctor Who, which I mostly only saw run through once on PBS over the course of years as a child, and often couldn't stay awake for the whole episode. So I'll remember a giant eyed alien with a high pitched voice, or a special effect that's a super neon glowing green on someone's skin, but very little else.
I've also discovered I remember the first few seasons of TNG and DS9 way better than the later seasons. I suspect because they went into syndication partway through their run so the first 50-70 episodes probably got rerun and rewatched a lot more. By the time the later seasons entered syndication... there were more episodes and I was rewatching less.