For to practise parkour is to seek fear on a daily basis, to confront it head-on, to face it naked and alone. In parkour, you are stripped to your essence. There is no equipment to rely on, no safety harnesses or padding to protect you, no teammate to take the brunt when you are tired. It’s you, and you alone. The only things that prevent you getting hurt or injured are your skills, your judgement, your ability – no one else’s.
~ Dan Edwards, from Moving Through Fear