I have this theory that all city people are sheep. They are herded around and placed in confined spaces like train carriages or walkways.
Parkour is an escape – it allows you to exist outside the constraints.
You form a relationship with your environment. For someone who practises Parkour a railing isn’t there – to others it is a barricade.
You form a bond with the obstacle. You might go back 100 times and find something new to do each time.