They Sleep in Bright Rooms
For people who are used to sleeping in pitch black, you might want to bring an eye mask with you to Korea. This is because, unlike in many other places, Korean children are taught to sleep in bright rooms where there may even be loud noises.
This is believed to help strengthen the nervous system of children and help them when they get older. For instance, having the ability to fall asleep on the bus for a couple of minutes to recharge their batteries.