the insomnia bug
I've come to realise the pattern - I stir in my sleep because #2 is stirring (he kicks, he stretches, he grunts). I get up and offer him milk (and gets rejected). the orchestra in the bedroom keeps me awake and my mind starts working over time again.
Too much to do, too little (me) time to do.
I get out of bed, enter the study room and boot up my laptop once again.