[chmod775]

Construction workers don't just wear them for reassurance either.

They protect the most vulnerable part of your body. You might not immediately go tell tales of it if you get hit in your helmet by anything but a small caliber or shrapnel (a large caliber will still inflict significant head trauma), but your chances of survival are way up from pretty much zero.

Also there might be all kinds of stuff flying around on a battlefield, and even if it isn't necessarily lethal, it's nice to not get hit in the head by a rock or whatever.