A super-bright flashlight is a critical self-defense (from all kinds of danger, man made or natural) tool. I'd put a cellphone as #1, bright light as #2, and some kind of very small knife/multitool (for cutting things, like seatbelts, not people) as #3.
It's crazy when people go straight to pepper spray, big knives, firearms, etc. for self defense, but don't carry simple things which are used far more often. There are costs (increased legal compliance, weight, training needs, risk if the item is taken from you, moral issues with hurting/killing other people) with each, vs. the benefit, but I can't think of any situations where the analysis for a tactical light isn't strongly in the "do" category.
Incidents in which tools have been useful to me personally: Traffic accidents (I've responded to about 20-25 in the past decade outside warzones, and probably seriously improved victim outcomes in a few, the last being 2 weeks ago); loud noises at night (ranging from two being shot and bleeding out in front of the loft in the tenderloin, to raccoons in trash cans, to everything in between), power failures sometimes incident to hurricanes, sandstorms, ..., all sorts of fun in warzones (mortars, people dropping cargo containers on top of other people by accident, porta-potties upended by high winds with person inside (!!!), street altercations (kid with knife, feral dogs, drunks, drug dealers on my front step blocking the entrance, ...), etc.
Plus the thousands of cardboard boxes, envelopes, plastic clamshells, bottles, cans, etc. which have fallen before me.
Okay - street altercations I know too much about - so a torch and a what? The challenge to me seems always to avoid it without escalating, so I don't think whipping out my box-cutter would be too advisable! Is there a procedure?
(not a very high-level HN contributory comment, I know)