Not only that but you feel that your body doesn't relax at night time, here in Stockholm right now there is sunlight up to 21-something, never getting completely dark after that until the sun is up again around 03.00, my body is still fully awake with energy until way past 23.00 when usually during winters I'll feel tired by 18.00 as it is dark since around 14.30-15.00.
I'm not Swedish but every Swede I know go through these cycles around the year, living here for 6 years hasn't changed much in terms of adaptation except that I just know that's how it works.
EDIT: Updated to elide personal information
They also cover the fact that there are multiple processes that affect the onset of sleep, and daylight is just one of them.
It's also possible that Scandinavians have some genetic differences that reduce the effect of long days on their ability to fall asleep.
Also I discovered recently that when tenting in mid-winter it is advisable to leave small ledlamp on. If you wake up in utter darkness, and you cannot remember where you are, panic attack can cause sever damage to the equipment. -- Double sleeping bags are the worst when zippers are not aligned anymore.
And yes. I have had a black bear stomping on my tent in Haida Gwaii. Yelling chased it away.