I've never found the need to shave my arms in a survival or normal outdoor activity. There is an apocryphal folkstory about Richard III meeting Saladin. Richard drew his great sword and cut an anvil in half. Saladin tossed a silk cloth in the air and let it float down over his scimitar, cutting in half as it passed. Both blades apparently did adequate work killing people.You can read the fantastic efforts to sharpen blades online and how they actually lose the ability to cut cigarette papers when to sharp, another activity I've never pursued outdoors. I expect someday lasers will replace knives, flashlights, fire starting devises, emergency signals and firearms. I am equally convinced there will be a forum devoted to tweeking them and complaining bitterly about their shortcomings.