I have also ridden on the back of someone else's bike, which was even scarier than being on my own bike. The practice of two people riding on the same bike is commonly used by families who only have one bike, and this is sometimes how siblings carpool to school. Biking is a whole lifestyle, which I think is really cool. It is a great way to get fresh air, exercise and to get to your destination quickly.
I think biking is absolutely connected to the environment and culture! The Netherlands is very flat because it is at sea level! In some places, it is even below sea level. This means the land is really flat and biking is not difficult. It is better to bike in the city because of the way the streets are designed. They really are built for bikes. This means biking can be even faster than going by car, especially because bikes can go where cars cannot.