It always amazes me how unprepared some folks are. It also amazes me that anyone would actually ASK that question IN a situation where the answer is obvious, like asking why you carry a flashlight when you pull one out in the darkness. I can understand a, "You carry a flashlight with you? Well isn't that convenient under the circumstances?", but questioning someone else's preparedness when the proof of its utility is evident just seems stupid.
I've had a watch on my wrist constantly since I was ~5-6 (I'm one of those that wears one almost 24/7 except in the shower. Yes, I'm one of those folks who sleeps with a watch on). Been carrying a SAK (Swiss Army Knife) of one size or another since I was about 10 (been EDC'ing a Swiss Champ XLT since that debuted, Swiss Champ for years before that, and smaller models before the SwissChamp). First started EDC'ing a light when the Solitaire debuted. Moved to a Photon button-cell LED when those came out, then to a Surefire 1xCR123 incan (this was before LEDs with decent output were available).
Just replaced my Fenix L2D R100 head on 1xAA body with a Quark QPA-G2 running a 14500 as my EDC light. I EDC it and use a flashlight every single day, even in the daytime, because sometimes you have to look at something indoors where the regular lighting doesn't reach too well.
I must be around different types of folks though, because I rarely ever (can't recall the last time) have someone ask me WHY I carry something when I pull it out to use it. I do occasionally get the, "Wow, you carry a flashlight on you?", as well as the, "Wow, that little thing is bright!", or "Dang, that's a big Swiss Army knife! Bet it's got just about everything doesn't it?", but not a, "Why do you carry XXXX?" when I'm obviously using it.
The flashlight has been invaluable numerous times with power outages, blown bulbs or just needing to light up something that is poorly lit (yep, like the back of a computer under a desk). The knife always comes in handy, and yes, for me, the XLT has benefits aside from impressing folks with its size. I've used the multiple bit driver on it numerous times, including on equipment needing Torx bits, which NO ONE usually has handy. Don't EDC a pen because I don't need to write much that often, but if I do, the SAK has a pen. Don't tend to EDC a 2nd light these days because I always have my phone on me and the LED lights on those are at least as good as (actually better than) a button-cell keychain light.
The most common comment I get from folks who know me, when I pull out any of my EDC items is, "Of course, you would have that with you".
Semper Peratus is better than numquam peratus.
Max