Sometimes I’ll be in bed just about to fall asleep when I hear a strange noise in the house. I wonder… is there someone breaking into my house? The first thing that I do is take a mental inventory of my bedroom. What do I have available to me that I can use to clobber or disable an intruder? I could bash the floor lamp into their face… maybe I could leap out of the room with a sideways kick and knock them backwards down the stairs… but then the sound doesn’t happen again and I fall asleep.