The Power of Prolog
I recall at college in 1989 our lecturer had brought in a chap who'd done an entire airline baggage management suite written in prolog (turbo prolog, to be more accurate).  The demo we saw was absolutely gorgeous -- real time updates on-screen to changes in baggage locations elsewhere (in the system).  This was on i386-equivalent machines, before anyone gets overly nonchalant.   He explained that he'd been up against two competing tenders - one in COBOL, the other in C - both higher priced and longer delivery times.Nonetheless, I still never really properly grokked prolog, as much as I tried.  I feel my brain had already been wired away from declarative languages.  Perhaps a poor cop-out.