There's always going to be delusionals who will get an unwarranted confidence in their abilities, but hey, just ignore the crazies. I've actually learnt quite a bit through video-games and other media. I've learnt weapon basics from first person shooters (no, I'm not considering myself special ops - but I know how to point and aim, I know to shoot in short bursts rather than just spray, I know that silencers affect aim, etc). I've learnt many a medical term from House, Scrubs, etc AND used these correctly with medical professionals. Games like Guitar Hero and DDR improve rhythm. Guitar Hero even teaches the basics of real guitar playing - hold the note and strum the chords, higher notes are actually further down the strings not up (watch someone play air guitar listening to rock songs - I bet they get that one wrong).
Most people will realise that what they're learning is either incorrect or highly watered down, but they have still learnt something. I wouldn't completely throw away the education factor in games.
I do quite like the comments about Star Wars and LOTR fans though. Just seems hilarious that we're ragging someone for making comments about how extensive their knowledge of a fictional universe is, and justifying it with "I've got much more knowledge of said fiction universe." It's fictional! Follow it as much as you want, but realise that the author(s) can create anything they want at any point, and often do. Then they can go back and retcon, rewriting it. They just make things up, and then fit it into the universe later. Particularly something like Star Wars, with the multiple writers involved. You're not aquiring regular knowledge that can be of any use, it's aquiring a list of useless (at least to the real world) information.