In earlier times it wasn't uncommon to read about how people were able to adjust to, and survive, many of life's daily problems and "inconveniences" with a jackknife, a handkerchief, some string or a twist of wire and a windproof lighter.
I remember carrying a Boy Scout pocket knife and an early Boy Scout branded pocket flashlight (2xAA batteries, flip-top w/metal case and a pathetic amount of light). Then came carrying a cobbled together pocket first aid kit. Those things came in handy
Eventually, the Boy Scout pocket knife was replaced with a Buck 110 on my belt and a Schrade Old Timer 80T Stockman pocket knife, and later still a Gerber FSII (carried in a pocket leather slip sheath) replaced the Buck 110, being lower key since it was carried in a front pocket; which was itself replaced with a Kershaw KAI 2040 single lockblade (also carried in a leather slip sheath, and I still own that one
).
Then came discovering the versatility and joys of SAK's being added to the mix.
A career in law enforcement made carrying a folding lockblade and one or another model SAK very practical and helpful. Ditto the advent of increasingly better pocketable flashlights, especially when working my final plainclothes assignment. I frequently used a small flashlight that slipped inside a sport or suit coat pocket a few times an hour throughout my normal day (when outside my office). Gotta be able to navigate low/no light conditions, see possible/actual threats, etc. Sure, I also kept backup lights in my unmarked car, especially larger ones, for those times when more light was needed, our caseload ran into the evening hours, etc.
Nowadays, in retirement, I still find I don't like to leave home without having at least a small high-power LED light and a knife or 2 (or 3) in my pockets. I even like having a knife and a small light on me just walking around the house. Sure, I have a nice expensive tool chest and tools, as well as some multi-tools, but it's the small and handy pocketable gear that's instantly helpful.
Like hot water, having access to conveniently portable light and a sharp blade are some of the handy conveniences of civilization.