The way I see it, Parkour is about the mindset first and foremost. The idea is to approach obstacles with an open mind, free of extraneous thought, and then allow your body to overcome it in the best way possible. In this way, everybody will have a different style of movement, because for each individual, there is a different method that may be deemed the "best" way to overcome the same obstacle. When people get into the argument of this or that is right or wrong in Parkour, they often are basing their argument on a fallacy, that one specific move is right or wrong. If you are focusing on individual moves, and your ability to perform the same move as somebody else (like saying, OK, he did a saut de chat, so I will try and emulate that movement) then you are negating not only your own person style, but also the basis of Parkour. That mindset is helpful when you are first starting out, because by copying a set of standardized movements, it becomes easier to learn and memorize the effeicient methods of overcoming obstacles. But once you have comfortably stored the options for effecient movement in your memory, you can stop thinking ahead to the next move and just allow the most effecient method for YOU to happen instincively. THIS is the idea of your own style within the construct of Parkour as it exists.