I tend to be paranoid, like my drill sergeant in basic training who had seen action in Korea and was constantly looked behind him, eyes always shifting. I figure, it pays to always err on the side of safety, and to never take your surroundings for granted. The truth is, I have not encountered trouble since I was a teenager, but then, I would go anywhere without a thought to any dangers that might present themselves. After all, in those days I was invulnerable.
In Vegas, or around any casino for that matter, I am always on guard simply because it's a place where people are expected to carry lots of money, and if I were a robber, what better place to ply my trade--so long as I knew where the cameras were and what the habits of security personnel were. It only takes a few seconds to point a gun and grab a wallet.