There are only a few mandatory insurances in Germany.
Social-insurances (in most cases only mandatory as an employee, most people who are selfemployed
are free to join the social security system if they wish or manage it on a private basis)
Since most people in Germany have a high coverage rate in terms of insurances it's also more common that you are held financially responsible for any damages you have caused. That's why some
insurances are very important and also not very expensive in general.