One of the fields I hayed in 1980 was the staging area for the Army helicopters flying to and from the Mt. St. Helens eruption that spring. I managed to find a discarded parachute with my disc mower on the back side. Now that's some tough material! I was hacking away with my dull pocket knife, and an old gentleman came out from a nearby house. He sized up the situation, then said "Why don't I loan you my pocket knife, and I'll go sharpen yours?" Great idea- his worked much better. When he brought mine back, I thanked him profusely- He said "No, thank YOU for giving an old man something useful to do today."
Never did even know his name, but that man could sure sharpen a knife!