I recently heard another dad suggest that we should allow our children to make their own decisions and do anything that isn't life threatening, immoral, or illegal.
This was good advice for me. I'm a controlling person and have the tendency to want to control my children and make sure they don't do anything they shouldn't do. While this may prevent more bruises and bumps and other sad consequences it probably isn't teaching them how to make decisions and understand consequences for themselves.
When we allow children to have a little space it does far more than just encourage them to learn from their own mistakes. It also teaches them to be decisive and independent. It also helps prepare them for the day they will leave the home and embark on being their own boss.