I wouldn't call it the wrong reason. But parkour is more of a discipline than pure "hey it's fun and look at what I can do", tho there is a tad bit of that in the community and in each of us. We get enjoyment out of it I don't think we would do it if it was torture for us to train parkour.
Anyway what Mattew was saying was parkour is about a mindset and then moving in that mindset. And a parkour mindset is either escape or search. So to put it simply parkour movements are supposed to be done efficiently to overcome an object and in the escape situation as quickly as possible. Without this mindset you are simply doing techniques/tricks or whatever you would want to call them.
There is much more to parkour than this, the community and the reason David Belle created the discipline and other resons linked within parkour.
To answer your question, check out the movements section of the forum and download some videos and research more at this site and other sites. And you learn some basic movements that will be the foundation and help you to start. Find a local forum to connect with people in your area.
P.S. to anybody who wants to correct me, such as mods or people who have a better understanding of parkour, if I have put any wrong information on here please do correct me so I don't spread wrong knowledge and I can learn myself.