I could never do it either. Eating nothing but rice and maybe fish if lucky. Sleeping on the ground. Wearing the same clothes day after day. Going to the bathroom in a hole on the ground if lucky. No thanks.
Try camping once. I know it might not be anywhere near some of the challenges on survivor, but you will get a good idea of what it is like in the wilderness.
Camping is also fun when you go with a bunch of people.