What's So Amazing?
Have you ever been asked the time and guessed it before you looked at your watch? If you're like most people, you were probably within half an hour at most. If you wake up around 3 AM, you might even guess it's around 3 AM before you check the clock.
To me, time sense seems just as amazing as perfect pitch. Ask me the time, and unless I've just been given a major time cue, I could easily be two hours off. Talk to me, leave, and come back, and as far as I know you could've been gome 10 minutes or an hour. Wake me up in the middle of the night and act like it's morning, and I'll be puzzling over why I'm inexplicably tired.
But to most people, time sense is nothing. You don't even know how you do it. You don't do any mental strategies for it. I watch the clock on the computer, I set alarms, I wait for environmental cues, I start a TV episode so I'll know when it's done 30 minutes has gone by - ask me how I keep track of time, and I can tell you a bunch of things. None of which get me up to the level of performance of someone with a time sense.
It's the same with perfect pitch, instant arithmetic, or photographic memory. And what's going on is that some low-level, unconscious part of your brain devotes itself to just that task. You don't think about it, you don't know how you do it - all you get is the answer.
And it really isn't so amazing to you.