I once heard a remark once that the Dutch are born on the bike lanes.
Clearly this notion is preposterous! Home births account for about 25% in the Netherlands while the rest are born in hospitals. But once the Dutch emerge from their mothers vaginal canal, they go from crib to curb, rolling on two wheels as early as possible.
This introduction sets the tone for a life long habit. This simple fact is what separates the bicycle from all other forms of transportation. For instance, one needs to be of certain age to acquire a licence to drive a car. But like walking, once this habit is learnt, stays with you until the twilight years.