And what grand magnanimity that is, considering they basically eloped with a bunch of Celts. Oh well, the Lannisters House of Glücksburg send their regards.
It didn't come for free of course, Norwegian kings were always quick to identify a tree-starved Icelander so the usual proceedings went 1) force/blackmail them into Christianity (optional), 2) send them to kill a few berserkers because nobody likes berserkers but it would be a shame to lose one's own men fighting them and 3) get them to compose complicated poetry on how you're the awesomest king.
Is it a law of nature that taking just a 30 minute nap on the couch should make one feel seriously hungover for the rest of the evening? Seems that way.
Yes. There's no easy wake-up power naps, only horrible, dizzy tiredness that lasts the rest of the evening and then you can't get sleep at night.