I was 23 when it aired, and I knew beforehand that it was a fictional drama. (Apparently, the original plan was to make out that it was a real live broadcast, but the BBC bottled out of that at the eleventh hour.) Even despite that, it scared the shit out of me. I've got the DVD, and I watch it every Halloween. Yes, I can see the bits that are cheesy and aritificial, the bad acting and the (now) fairly recognizable supporting actors. It doesn't matter. The moment of real impact is Pipes appearing in the curtains. On subsequent viewings, he starts popping up more and more. I'm 40 now, and after watching Ghostwatch I'm still scared to go up stairs in the dark for a few days - I think it successfully hits some really deep primal fear.