Every now and then the awareness that I'm not 23 anymore slices through me, I have a little shivery moment of terror and self-recrimination, like that instant where you've just said the most terrible thing to someone, the words have left your mouth and you can't get them back.

It's a bad feeling but I'm not even sure exactly how. Regrets? Unavailable options? Simple mortality? Really none of those things, at least not in an obvious way. More like a sudden feeling that you can't stop, life doesn't let you slow it down to get your bearings, it just plods inexorably forward, events rush by no matter how fast or slow you're going, or whether you're moving at all.