The Netherlands has about 17 million people, the vast majority of which are bicycling regularly and own one or more bicycles. They bicycle for pretty much any human activity, starting with the morning commute to office, university or school. They bicycle to go shopping, to come home at lunch time, to go out at night, for recreation, for exercise, and more.
This adds up to millions of cycle trips per day across the Netherlands.
Bicycling is safe in the Netherlands partly because of the widespread dedicated bicycling infrastructure, and partly due to the number of bicyclists.