All people are like animals- they may bite without "reason" or provocation. One need not be a twitching, spastic freak to be guarded and conscious of personal space.
Let me add this: learn to think like a predator. I had a conversation with a friend, local gunshop owner, about some alterations I'd recently completed on a rifle to make it more user-friendly. He looked at me with a blank expression for a moment, then said, "That's cool, I just don't think that way..."
Though I did not say it, my thought was, he'd better start. I could easily be inside his shop, after hours, within 20 minutes, with most, if not all, his inventory out in 90. Now, it isn't that I'm feloniously inclined, I just view the world through deconstructionist eyes.
Looking at the world from the perspective of, "How would I take what I want?", it filters unnecessary crap. If you were going to jack someone, how close would you want to be? Kidnapping, rape? Con them out of $20? Some people are horrified when hearing this. The simple truth is, they do not want to be able to identify hunting behaviors. If they did, they might be forced to concede that they are violating the Rule of Stupids, and are Doing Stupid Things, Assosciating with Stupid People, and going to Stupid Places. Changing might involve less personal amusement, and might hurt some friends feelings...