It's funny also, the things that are nearly undisputed as necessary, where as a good blade is so controversial.
Almost nobody here will argue against water purification or filtration for instance, yet the amount of water that may be potentially fatal to a healthy hiker is almost nil in this country.
I've drank unfiltered water the world over and never been sick from it, yet I've become convinced myself that I need to be taking precautions. Even the sicknesses that someone can get, are almost never that serious, no matter how embarrassing or inconvenient. Yet many people carry nearly a lb of filtration equipment or, even better, chemicals to make the water safe. Which I've always found ironic, since chemicals are the only thing I fear in water(yes yes I know, they're all safe and have been used for years, yay!), not bacteria, generally.
People carry heavy multi-tools, justified by the "multi" aspect of it, yet I've never met one that was as light as my main blade, or any more useful at most of it's functions than my blade.
It's a tool, and a very useful one. I can cut, gouge, pry, scrape, screw, unscrew any normal type fastener, etc. The one thing I see a multi-tool having over a knife are pliers, but some light fishing pliers would probably be more effective, since most of the multitool pliers are crap.
I'll leave the rain pants behind, they're truly useless in my book. I won't ever leave my knife. It sees action every trip. My rain pants never did, and they weighed 3x as much. Keep telling yourself you use them when you do laundry. ;P