It used to be an insane hour to me. At a quarter to 2 o'clock at night I would be fast asleep, happy to dream, cuddled, hassle-free.
Only after I joined university, that hour was witnessing my passion to read (I hardly ever remember learning something so late at night, but reading - yes, that was usually the case;).
Then, obviously, the coming-back-from-parties hour came on scene. Quite late in life, I agree; but you know, everyone's different. Until then, I didn't know birds are awake in the middle of the night.
Now I know it again. Not too often, though. Throughout my motherhood years (sounds like few ages, where in fact it's no more than 6 years) I developed a pretty clever ability to reach that deep sleep phase within seconds. To the detriment of my husband's night dreams. Obviously.