Instead of trying to explain or justify it, I would use first-hand experiences to illustrate your point.

Maybe a camping trip would help. You could conveniently forget your flashlights at home. Show up at the campground at dark. Attempt to set-up tent. (Of course you'll suffer from not much sleep that night).

Or perhaps removing all the knives from the kitchen would work. When your wife asks why you did so, mention you didn't think she needed them anymore. (You'll probably suffer by not getting a meal).

Granted, I'm being a little cynical. But I've put together emergency kits and given gifts of a preparedness nature and most of them sit on a shelf somewhere gathering dust.

Sadly, unless most people have a need or reason to use the tools, they can't be convinced of how useful they truly are.