I've got a few questions. First of all I've heard alot that willpower is the cause of sometimes superhuman efforts like keeping awake for several days in a row, walking beyond one's physical capability, performing even when under severe resistance or extreme pain etc. What I first of all want to know is all this (or even a part of it) true? And how does will power actually cause such super human efforts? I'd also like to know how exactly does one increase his/her willpower (sorry if its a stupid question but I'd really like to know)? Is it by lengthy and strenous physical activity or also by doing stuff which normally you'd hate and avoid( where the challenge lies mentally)? Lastly I'd like to know how does one increase his stamina? Is it just by regularly doing strenous physical exercises or something else?