Let me first note that hurting yourself on the above-mentioned inflatable
jumping thingies is not an easy thing to do. In fact, it takes a great deal of will power
and determination, coupled with a complete lack of manual dexterity
and grace. Lucky for me, I possess the perfect balance of these characteristics.
Ok, so here's how you do it. Since the jumping thingies are normally set up in a park of some sort, make sure to wear white socks that have just come out of the washing machine. The embarrassment caused by the contrast between the black bottom of your socks and the white top will be a lovely precursor to the pain that is soon to follow.
Next, grab a friend and get in line for the giant inflatable obstacle course (make sure that this friend is in infinitely better shape than you are). Take off your shoes and begin soiling your fresh socks. For added effect, wear white pants and sit on the ground, acquiring a giant green grassy stain on the bum. Then stand up and run around a lot, drawing attention to the stain that you haven't quite noticed yet.
When the race begins, trip. When you have had adequate time to recuperate, get up and trip again. Notice that you have yet to reach the inflatable bouncy thing.
Jump onto the bouncy thing with a wild yell, flailing your arms and legs. Dive under the first obstacle, and as soon as all eyes are fixed on you, fall off the bouncy thing. Notice the growing bruise underneath the grass stain on your pants.
When you have realized that your friend is at least twice as far along the course as you are, pick up speed and launch yourself into the next obstacle (which happens to be a hole you have to crawl through). Make sure you launch yourself with such force that your body becomes stuck inside the hole and you have to be rescued by your friend. This is of key importance.
After you have escaped the evil inflatable hole obstacle, throw your kindly friend to the ground and run over them to the next obstacle, causing them to become increasingly angry and beat you with the giant phallic inflatable poles. Fall down. Again, notice the growing bruise on your ass.
Finish the race by throwing yourself not on the mat, not on the soft grass, but on the big pile of hardened dirt next to the grass. This will increase your bruised to healthy skin ratio in a big way.
Thank your friend, who is already at the hot dog stand buying lunch, and go home to nurse your wounds. If you successfully complete all of these steps, you too can be counted among the ranks of the graceless and determined!
If I can do it, anybody can!