I do think that Erik Weihenmayer is an inspiration. He showed people you can do anything, no matter what disabilities you have. Its hard enough to climb a moutain when you can see, I can only imagine how haid it is blind.
The most challenging thing i ever had to do was run 5miles without stopping. I was a good runner but i could only run about 2 miles then I would get to tired and walk. But one day I made a bet with my friend that I could beat her in running 5miles non-stop. I won and I got 25dollars out of the deal!