Furious Tiger hit it.
Do you really need a reason beyond 9/11 and the Eastern power outage as justification for flashlights and other tools?
Sure, this doesn't mean that you have to go out and buy a $100+ Surefire or other super high-end light, but I think you'd be positively nuts to venture out in the world without at least an Arc AAA or similar.
Lots of people carry firearms everyday. Have you ever carried one, gadgetnut? It is a big, fat PITA. (Pain in the ***.)
Yet thousands, possibly millions, of people carry them every day. Do you know why? Because all it takes is one time for you to need a gun and not have it and it could mean the difference between your life or death.
I firmly believe that a flashlight and knife are in the same category as a firearm; positively indispensable everyday carry items that no person should be without.
It could take but one time for you to be caught without your knife, flashlight, or firearm for it to mean your life.
On a lighter note, (and keeping it on topic /ubbthreads/images/graemlins/smile.gif ) in all but the most extreme cases, a flashlight will simply make your life easier and more convenient. It could mean the difference between stumbling and perhaps falling on a dark walkway, or cruising along smoothly, avoiding bumps and holes, thanks to your flashlight. Again, even a simple Arc AAA is sufficient for most people, myself included. (I choose to carry more than that, but that's just me...)
I personally am a city dweller, and as such, only rarely have use for a flashlight. Well, about once or twice a week. However, I am going to invest money in an ultra-bright Surefire (hopefully the L5 or L6 when they come out!!! /ubbthreads/images/graemlins/grin.gif ) for use as a blinding weapon and prelude to more serious tools.
It all comes down to your personal situation, preferences, finances, etc.
Some people have no problem spending the money on high-end lights and other things, even if they never get used.
Some people can't and don't or won't.
I'd say if you REALLY want a Surefire, get it as a special treat for yourself. I guarantee it will come in handy at some point in your life. A Surefire is a quality tool, one that will likely outlast your lifetime, and would be nice to have around.
Remember: always be prepared.