I head that riding through the Netherlands is a dream. That dream came true! The Netherlands maintain separated bike paths from the car roads and have their own traffic lights that drivers understand that when it is a green light for bicycles, then cyclists have the right of way when a car is making a left or right turn.
Many cars are courteous for cyclists because they are a cyclist or have family and friends are a cyclist.
Riding happens to also be easy because most of the terrain is flat as most of it is under sea level.