Thinking more upon it I am wondering what possible occurrence's could lead to one losing every piece of gear but their PSK and knife while On foot?

Wandering off from camp for what ever reason is just way tooo....Simple? When dealing with people who put their mind to making a PSK and picking a Knife and Considering preparations for survival why would one such individual Not take some form of gear with them? If you Worry about survival enough to make a PSK wouldnt your first understandment is wandering off from camp without proper gear can result in what your preparing for and attempting to avoid?

The only other situations I can Think about is Encountering a Wild animal and using pack to distract it, falling into water, Falling down large hill.

Any Ideas on this?