The reason is as given by @Cowpeke.

This used to be a feature on all Volvo cars a few years back. You could not turn off the lights even if you wanted to. Apparently,Sweden gets frequent and abrupt fog in the middle of the day making it very dangerous on the roads. Thus they passed a rule that cars must be driven with lights on ALL the time,day and night! Thus Volvo makers decided to connect the light switch to the ignition permanently.....

Anyone living in Sweden to confirm whether this is true?

Behind the gardens...Behind the wall...Under the tree (Including: Red...Dark Blue...Yellow)

Speaking of full lights at night,the most dangerous are the ones from the car behind you!!

The one in front lasts only a few seconds,but the car behind you can blind you for very many minutes....even half an hour on a busy road. The problem is that many idiot drivers don't know that they are blinding you from behind!

Behind the gardens...Behind the wall...Under the tree (Including: Red...Dark Blue...Yellow)

Many cars now have a prismatic rear-view mirror... that can be tilted to reduce the brightness of glare of headlights from car behind..... but you still have a view of the rear.

For those that don't,they can be easily swivelled to change position....