Murray Fleming knows he will still be amazed even after 10 hectic years involved with New Zealand's maddest endurance race.
As organiser of the annual Burgen Tough Guy and Gal Challenge, he's watched it mushroom from 432 people at the first one at Rotorua, to 42,000 hardy souls who have braved the mud and mayhem since.
Events were also now held in Auckland, Wellington and Palmerston North.
Fleming has seen competitors of all shapes and sizes, dressed in everything from tutus to superhero outfits - and he still managed to be surprised yesterday.
"Right from the beginning, the bottom line has been, this has to be a lot of fun," he said.