Rhuby, I was taught the times table up to 12 as well, though I'm not quite sure why. Perhaps it's because 12x12 has a specific name (gross), while nothing closely higher than it does.
I always, whenever possible, put my clocks in 24-hour time and also irritatedly correct my acquaintances who scoff at my use of "military time". Rather than it's simplicity, I'd say I use it more for it's relative novelty (over here) and because it's part of my meager attempt for feel more international. Though I must ask, do you actually say "14 o'clock" etc? I was of the impression that, at least in the UK, the 24-hour clock was used mainly for official time keeping and schedules, while people still say "2 o'clock." I'm remember getting an odd look the one time I said something like "it's thirteen twenty-five right now."
