To whom it may concern:
This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.
(After the critical success of part II, and the strong box office sales of part III in spite of mixed reviews, will part IV finally see the June Open Thread jump the shark?)
Checking wikipedia, it looks possible but not likely that Harry could have seen the list in 1991.
Well, he and his father are described as being huge science fiction fans, so it's not that unlikely that they heard about the list at conventions, or had someone show them an early version of the list printed from email discussions, even if they didn't have Internet access back then.