Those kinds of flags are the only way I can remember what I like. My memory is poor enough that I lose most details about books and movies within a few months, but if I really liked something, that 5-Yay rating sticks around for years.

Hmm, I guess that's why part of my brain still thinks Moulin Rouge, which I saw on a very enjoyable date, and never really had the urge to actually watch again, is one of my favorite movies.

Compression seems a fine analogy to me, as long as we're talking about mp3's and flv's, rather than zip's and tar's.