requires a safe environment for people to fail miserably without the harsh or sharp feedback.
For example, when children play with each other it is often fast paced, rough, and at times it looks dangerous. Except for the life threatening or crippling instances of child play, most adults should not interfere and protect the child from every little instance of pain. As babies, this is understandable. They are not familiar with their environment or themselves. However, as children age, they have to learn how to play and learn the limitations of what is safe and what is dangerous.
Especially when children begin to play with each other. It usually starts at a slow pace and builds up into a momentous rancor that is hard to keep track of. In time, a child may get a scraped knee or a cut, but that is part of the experience and beginning of their education in taking risks.
If a child never experiences pain, they will be ignorant of what kinds of risks to take as an adolescent and as an adult. As this ignorance progresses, it only builds up. Think of the absorbant college student that intakes an absurd amount of any substance. Yes, that was me.
Now, this may not be true of all children, but I would argue it is true for most. They learn through repetitive experiences in life until the moment it begins to stick. The transition then goes from learning to knowing and through a slow cycle of relearning and reconfirmations. Without the room to play and to make mistakes, the person takes an unfamiliar risk that could be a crippling mistake (the drunk college student).
Allowing a safe environment to play creates the opportunities for the children to learn how to take calculated risks that offer them the opportunity to have fun and get injured in small ways.
As adults, we can design these environments and craft play experiments that allow for making minute risky choices. In time, the repeated practice becomes a behavior. Hopefully, it becomes a key part of the future adult who will learn how to think and make good choices.