Morning...yawn

Why of why does son have so much energy and noise first thing in the morning?  I should add that its only the on weekends and breaks.  On school days, he grunts, moans and will lie down on any flat surface because he's "soooooooo tired".  He talked non-stop this am (and I paid how much for private speech therapy for this verbal ability?) and wouldn't sit still while I desperately tried to chug my coffee and clear my head.  At least he slept until 7 again.  Many weekends, he will be up at 6am and full of energy despite me having to literally drag him out of bed on weekdays at 6:30. 
He's finally settling down now to his computer and "Free Realms" until its time to read.  We haven't planned anything today although we tossed around the idea of a movie - which means trying to get son and his sister to compromise on which movie to see, lucky me.  I'm going to try to get the daughter to pick 2 acceptable choices and then have son choose between the 2 so this way, she gets to see something she wants and he feels like he had control and chose.