I recognized this problem even as a teen, whenever something really moved me. I left the theater after ET vowing not to see it again as a repeat viewing I just know wouldn't live up to what I had just experienced. I said the same thing after reading the first volume of Piers Anthony's Bio of a Space Tyrant, so my taste was questionable 
That said, I think most things hold up for me when I go back to them as in many ways I'm still a kid. I told my sister when she adopted my niece that I would be able to relate to the kid on the same emotional and intellectual level, and that is proving to indeed be the case. The low budget stuff like Land of the Lost holds up because at the core it's well written and the bad acting is part of the "charm".
Actually, now that I think of it, this type of problem affects books much more then movies. Coming back to an old comfort book after a decade or two of expanding your horizons lets you see the real subtexts or bad writing that never jumped out at you before. With a two hour movie you can keep that initial happiness at seeing an old friend going until the credits, but with a book that might take you a few days things are going to work into your thoughts and get you to re-examine the story more closely.
(Going back to Piers Anthony is damned hard)