I saw Legend ages ago, on VCR. Some friends and I were just curious enough to see how it was, largely because of Tim Curry. I don't remember much of it. Again, never much of a fantasy/sci-fi type. But I remember the visuals, and I remember being somewhat impressed by them.
Why I couldn't remember the overall plot isn't something I can comment on. I don't think it was overly complex. I think I actually saw the movie again some years later. Like the first time, the story didn't leave a big impression on me. It wasn't horrible. I didn't hate it. I didn't even mind Tom Cruise, an actor I find continually looks worse for being surrounded by crack supporting actors.
I just don't remember it beyond the visuals. Mr. Wright unpacks why this might be the case.